1 //===- BugReporter.cpp - Generate PathDiagnostics for bugs ----------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines BugReporter, a utility class for generating 10 // PathDiagnostics. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 15 #include "clang/AST/Decl.h" 16 #include "clang/AST/DeclBase.h" 17 #include "clang/AST/DeclObjC.h" 18 #include "clang/AST/Expr.h" 19 #include "clang/AST/ExprCXX.h" 20 #include "clang/AST/ParentMap.h" 21 #include "clang/AST/Stmt.h" 22 #include "clang/AST/StmtCXX.h" 23 #include "clang/AST/StmtObjC.h" 24 #include "clang/Analysis/AnalysisDeclContext.h" 25 #include "clang/Analysis/CFG.h" 26 #include "clang/Analysis/CFGStmtMap.h" 27 #include "clang/Analysis/PathDiagnostic.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/Checker.h" 36 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 37 #include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h" 38 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 39 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h" 40 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 41 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h" 42 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h" 43 #include "llvm/ADT/ArrayRef.h" 44 #include "llvm/ADT/DenseMap.h" 45 #include "llvm/ADT/DenseSet.h" 46 #include "llvm/ADT/FoldingSet.h" 47 #include "llvm/ADT/None.h" 48 #include "llvm/ADT/Optional.h" 49 #include "llvm/ADT/STLExtras.h" 50 #include "llvm/ADT/SmallPtrSet.h" 51 #include "llvm/ADT/SmallString.h" 52 #include "llvm/ADT/SmallVector.h" 53 #include "llvm/ADT/Statistic.h" 54 #include "llvm/ADT/StringRef.h" 55 #include "llvm/ADT/iterator_range.h" 56 #include "llvm/Support/Casting.h" 57 #include "llvm/Support/Compiler.h" 58 #include "llvm/Support/ErrorHandling.h" 59 #include "llvm/Support/MemoryBuffer.h" 60 #include "llvm/Support/raw_ostream.h" 61 #include <algorithm> 62 #include <cassert> 63 #include <cstddef> 64 #include <iterator> 65 #include <memory> 66 #include <queue> 67 #include <string> 68 #include <tuple> 69 #include <utility> 70 #include <vector> 71 72 using namespace clang; 73 using namespace ento; 74 using namespace llvm; 75 76 #define DEBUG_TYPE "BugReporter" 77 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)"); 83 84 BugReporterVisitor::~BugReporterVisitor() = default; 85 86 void BugReporterContext::anchor() {} 87 88 //===----------------------------------------------------------------------===// 89 // PathDiagnosticBuilder and its associated routines and helper objects. 90 //===----------------------------------------------------------------------===// 91 92 namespace { 93 94 /// A (CallPiece, node assiciated with its CallEnter) pair. 95 using CallWithEntry = 96 std::pair<PathDiagnosticCallPiece *, const ExplodedNode *>; 97 using CallWithEntryStack = SmallVector<CallWithEntry, 6>; 98 99 /// Map from each node to the diagnostic pieces visitors emit for them. 100 using VisitorsDiagnosticsTy = 101 llvm::DenseMap<const ExplodedNode *, std::vector<PathDiagnosticPieceRef>>; 102 103 /// A map from PathDiagnosticPiece to the LocationContext of the inlined 104 /// function call it represents. 105 using LocationContextMap = 106 llvm::DenseMap<const PathPieces *, const LocationContext *>; 107 108 /// A helper class that contains everything needed to construct a 109 /// PathDiagnostic object. It does no much more then providing convenient 110 /// getters and some well placed asserts for extra security. 111 class PathDiagnosticConstruct { 112 /// The consumer we're constructing the bug report for. 113 const PathDiagnosticConsumer *Consumer; 114 /// Our current position in the bug path, which is owned by 115 /// PathDiagnosticBuilder. 116 const ExplodedNode *CurrentNode; 117 /// A mapping from parts of the bug path (for example, a function call, which 118 /// would span backwards from a CallExit to a CallEnter with the nodes in 119 /// between them) with the location contexts it is associated with. 120 LocationContextMap LCM; 121 const SourceManager &SM; 122 123 public: 124 /// We keep stack of calls to functions as we're ascending the bug path. 125 /// TODO: PathDiagnostic has a stack doing the same thing, shouldn't we use 126 /// that instead? 127 CallWithEntryStack CallStack; 128 /// The bug report we're constructing. For ease of use, this field is kept 129 /// public, though some "shortcut" getters are provided for commonly used 130 /// methods of PathDiagnostic. 131 std::unique_ptr<PathDiagnostic> PD; 132 133 public: 134 PathDiagnosticConstruct(const PathDiagnosticConsumer *PDC, 135 const ExplodedNode *ErrorNode, 136 const PathSensitiveBugReport *R); 137 138 /// \returns the location context associated with the current position in the 139 /// bug path. 140 const LocationContext *getCurrLocationContext() const { 141 assert(CurrentNode && "Already reached the root!"); 142 return CurrentNode->getLocationContext(); 143 } 144 145 /// Same as getCurrLocationContext (they should always return the same 146 /// location context), but works after reaching the root of the bug path as 147 /// well. 148 const LocationContext *getLocationContextForActivePath() const { 149 return LCM.find(&PD->getActivePath())->getSecond(); 150 } 151 152 const ExplodedNode *getCurrentNode() const { return CurrentNode; } 153 154 /// Steps the current node to its predecessor. 155 /// \returns whether we reached the root of the bug path. 156 bool ascendToPrevNode() { 157 CurrentNode = CurrentNode->getFirstPred(); 158 return static_cast<bool>(CurrentNode); 159 } 160 161 const ParentMap &getParentMap() const { 162 return getCurrLocationContext()->getParentMap(); 163 } 164 165 const SourceManager &getSourceManager() const { return SM; } 166 167 const Stmt *getParent(const Stmt *S) const { 168 return getParentMap().getParent(S); 169 } 170 171 void updateLocCtxMap(const PathPieces *Path, const LocationContext *LC) { 172 assert(Path && LC); 173 LCM[Path] = LC; 174 } 175 176 const LocationContext *getLocationContextFor(const PathPieces *Path) const { 177 assert(LCM.count(Path) && 178 "Failed to find the context associated with these pieces!"); 179 return LCM.find(Path)->getSecond(); 180 } 181 182 bool isInLocCtxMap(const PathPieces *Path) const { return LCM.count(Path); } 183 184 PathPieces &getActivePath() { return PD->getActivePath(); } 185 PathPieces &getMutablePieces() { return PD->getMutablePieces(); } 186 187 bool shouldAddPathEdges() const { return Consumer->shouldAddPathEdges(); } 188 bool shouldGenerateDiagnostics() const { 189 return Consumer->shouldGenerateDiagnostics(); 190 } 191 bool supportsLogicalOpControlFlow() const { 192 return Consumer->supportsLogicalOpControlFlow(); 193 } 194 }; 195 196 /// Contains every contextual information needed for constructing a 197 /// PathDiagnostic object for a given bug report. This class and its fields are 198 /// immutable, and passes a BugReportConstruct object around during the 199 /// construction. 200 class PathDiagnosticBuilder : public BugReporterContext { 201 /// A linear path from the error node to the root. 202 std::unique_ptr<const ExplodedGraph> BugPath; 203 /// The bug report we're describing. Visitors create their diagnostics with 204 /// them being the last entities being able to modify it (for example, 205 /// changing interestingness here would cause inconsistencies as to how this 206 /// file and visitors construct diagnostics), hence its const. 207 const PathSensitiveBugReport *R; 208 /// The leaf of the bug path. This isn't the same as the bug reports error 209 /// node, which refers to the *original* graph, not the bug path. 210 const ExplodedNode *const ErrorNode; 211 /// The diagnostic pieces visitors emitted, which is expected to be collected 212 /// by the time this builder is constructed. 213 std::unique_ptr<const VisitorsDiagnosticsTy> VisitorsDiagnostics; 214 215 public: 216 /// Find a non-invalidated report for a given equivalence class, and returns 217 /// a PathDiagnosticBuilder able to construct bug reports for different 218 /// consumers. Returns None if no valid report is found. 219 static Optional<PathDiagnosticBuilder> 220 findValidReport(ArrayRef<PathSensitiveBugReport *> &bugReports, 221 PathSensitiveBugReporter &Reporter); 222 223 PathDiagnosticBuilder( 224 BugReporterContext BRC, std::unique_ptr<ExplodedGraph> BugPath, 225 PathSensitiveBugReport *r, const ExplodedNode *ErrorNode, 226 std::unique_ptr<VisitorsDiagnosticsTy> VisitorsDiagnostics); 227 228 /// This function is responsible for generating diagnostic pieces that are 229 /// *not* provided by bug report visitors. 230 /// These diagnostics may differ depending on the consumer's settings, 231 /// and are therefore constructed separately for each consumer. 232 /// 233 /// There are two path diagnostics generation modes: with adding edges (used 234 /// for plists) and without (used for HTML and text). When edges are added, 235 /// the path is modified to insert artificially generated edges. 236 /// Otherwise, more detailed diagnostics is emitted for block edges, 237 /// explaining the transitions in words. 238 std::unique_ptr<PathDiagnostic> 239 generate(const PathDiagnosticConsumer *PDC) const; 240 241 private: 242 void updateStackPiecesWithMessage(PathDiagnosticPieceRef P, 243 const CallWithEntryStack &CallStack) const; 244 void generatePathDiagnosticsForNode(PathDiagnosticConstruct &C, 245 PathDiagnosticLocation &PrevLoc) const; 246 247 void generateMinimalDiagForBlockEdge(PathDiagnosticConstruct &C, 248 BlockEdge BE) const; 249 250 PathDiagnosticPieceRef 251 generateDiagForGotoOP(const PathDiagnosticConstruct &C, const Stmt *S, 252 PathDiagnosticLocation &Start) const; 253 254 PathDiagnosticPieceRef 255 generateDiagForSwitchOP(const PathDiagnosticConstruct &C, const CFGBlock *Dst, 256 PathDiagnosticLocation &Start) const; 257 258 PathDiagnosticPieceRef 259 generateDiagForBinaryOP(const PathDiagnosticConstruct &C, const Stmt *T, 260 const CFGBlock *Src, const CFGBlock *DstC) const; 261 262 PathDiagnosticLocation 263 ExecutionContinues(const PathDiagnosticConstruct &C) const; 264 265 PathDiagnosticLocation 266 ExecutionContinues(llvm::raw_string_ostream &os, 267 const PathDiagnosticConstruct &C) const; 268 269 const PathSensitiveBugReport *getBugReport() const { return R; } 270 }; 271 272 } // namespace 273 274 //===----------------------------------------------------------------------===// 275 // Base implementation of stack hint generators. 276 //===----------------------------------------------------------------------===// 277 278 StackHintGenerator::~StackHintGenerator() = default; 279 280 std::string StackHintGeneratorForSymbol::getMessage(const ExplodedNode *N){ 281 if (!N) 282 return getMessageForSymbolNotFound(); 283 284 ProgramPoint P = N->getLocation(); 285 CallExitEnd CExit = P.castAs<CallExitEnd>(); 286 287 // FIXME: Use CallEvent to abstract this over all calls. 288 const Stmt *CallSite = CExit.getCalleeContext()->getCallSite(); 289 const auto *CE = dyn_cast_or_null<CallExpr>(CallSite); 290 if (!CE) 291 return {}; 292 293 // Check if one of the parameters are set to the interesting symbol. 294 unsigned ArgIndex = 0; 295 for (CallExpr::const_arg_iterator I = CE->arg_begin(), 296 E = CE->arg_end(); I != E; ++I, ++ArgIndex){ 297 SVal SV = N->getSVal(*I); 298 299 // Check if the variable corresponding to the symbol is passed by value. 300 SymbolRef AS = SV.getAsLocSymbol(); 301 if (AS == Sym) { 302 return getMessageForArg(*I, ArgIndex); 303 } 304 305 // Check if the parameter is a pointer to the symbol. 306 if (Optional<loc::MemRegionVal> Reg = SV.getAs<loc::MemRegionVal>()) { 307 // Do not attempt to dereference void*. 308 if ((*I)->getType()->isVoidPointerType()) 309 continue; 310 SVal PSV = N->getState()->getSVal(Reg->getRegion()); 311 SymbolRef AS = PSV.getAsLocSymbol(); 312 if (AS == Sym) { 313 return getMessageForArg(*I, ArgIndex); 314 } 315 } 316 } 317 318 // Check if we are returning the interesting symbol. 319 SVal SV = N->getSVal(CE); 320 SymbolRef RetSym = SV.getAsLocSymbol(); 321 if (RetSym == Sym) { 322 return getMessageForReturn(CE); 323 } 324 325 return getMessageForSymbolNotFound(); 326 } 327 328 std::string StackHintGeneratorForSymbol::getMessageForArg(const Expr *ArgE, 329 unsigned ArgIndex) { 330 // Printed parameters start at 1, not 0. 331 ++ArgIndex; 332 333 return (llvm::Twine(Msg) + " via " + std::to_string(ArgIndex) + 334 llvm::getOrdinalSuffix(ArgIndex) + " parameter").str(); 335 } 336 337 //===----------------------------------------------------------------------===// 338 // Diagnostic cleanup. 339 //===----------------------------------------------------------------------===// 340 341 static PathDiagnosticEventPiece * 342 eventsDescribeSameCondition(PathDiagnosticEventPiece *X, 343 PathDiagnosticEventPiece *Y) { 344 // Prefer diagnostics that come from ConditionBRVisitor over 345 // those that came from TrackConstraintBRVisitor, 346 // unless the one from ConditionBRVisitor is 347 // its generic fallback diagnostic. 348 const void *tagPreferred = ConditionBRVisitor::getTag(); 349 const void *tagLesser = TrackConstraintBRVisitor::getTag(); 350 351 if (X->getLocation() != Y->getLocation()) 352 return nullptr; 353 354 if (X->getTag() == tagPreferred && Y->getTag() == tagLesser) 355 return ConditionBRVisitor::isPieceMessageGeneric(X) ? Y : X; 356 357 if (Y->getTag() == tagPreferred && X->getTag() == tagLesser) 358 return ConditionBRVisitor::isPieceMessageGeneric(Y) ? X : Y; 359 360 return nullptr; 361 } 362 363 /// An optimization pass over PathPieces that removes redundant diagnostics 364 /// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both 365 /// BugReporterVisitors use different methods to generate diagnostics, with 366 /// one capable of emitting diagnostics in some cases but not in others. This 367 /// can lead to redundant diagnostic pieces at the same point in a path. 368 static void removeRedundantMsgs(PathPieces &path) { 369 unsigned N = path.size(); 370 if (N < 2) 371 return; 372 // NOTE: this loop intentionally is not using an iterator. Instead, we 373 // are streaming the path and modifying it in place. This is done by 374 // grabbing the front, processing it, and if we decide to keep it append 375 // it to the end of the path. The entire path is processed in this way. 376 for (unsigned i = 0; i < N; ++i) { 377 auto piece = std::move(path.front()); 378 path.pop_front(); 379 380 switch (piece->getKind()) { 381 case PathDiagnosticPiece::Call: 382 removeRedundantMsgs(cast<PathDiagnosticCallPiece>(*piece).path); 383 break; 384 case PathDiagnosticPiece::Macro: 385 removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(*piece).subPieces); 386 break; 387 case PathDiagnosticPiece::Event: { 388 if (i == N-1) 389 break; 390 391 if (auto *nextEvent = 392 dyn_cast<PathDiagnosticEventPiece>(path.front().get())) { 393 auto *event = cast<PathDiagnosticEventPiece>(piece.get()); 394 // Check to see if we should keep one of the two pieces. If we 395 // come up with a preference, record which piece to keep, and consume 396 // another piece from the path. 397 if (auto *pieceToKeep = 398 eventsDescribeSameCondition(event, nextEvent)) { 399 piece = std::move(pieceToKeep == event ? piece : path.front()); 400 path.pop_front(); 401 ++i; 402 } 403 } 404 break; 405 } 406 case PathDiagnosticPiece::ControlFlow: 407 case PathDiagnosticPiece::Note: 408 case PathDiagnosticPiece::PopUp: 409 break; 410 } 411 path.push_back(std::move(piece)); 412 } 413 } 414 415 /// Recursively scan through a path and prune out calls and macros pieces 416 /// that aren't needed. Return true if afterwards the path contains 417 /// "interesting stuff" which means it shouldn't be pruned from the parent path. 418 static bool removeUnneededCalls(const PathDiagnosticConstruct &C, 419 PathPieces &pieces, 420 const PathSensitiveBugReport *R, 421 bool IsInteresting = false) { 422 bool containsSomethingInteresting = IsInteresting; 423 const unsigned N = pieces.size(); 424 425 for (unsigned i = 0 ; i < N ; ++i) { 426 // Remove the front piece from the path. If it is still something we 427 // want to keep once we are done, we will push it back on the end. 428 auto piece = std::move(pieces.front()); 429 pieces.pop_front(); 430 431 switch (piece->getKind()) { 432 case PathDiagnosticPiece::Call: { 433 auto &call = cast<PathDiagnosticCallPiece>(*piece); 434 // Check if the location context is interesting. 435 if (!removeUnneededCalls( 436 C, call.path, R, 437 R->isInteresting(C.getLocationContextFor(&call.path)))) 438 continue; 439 440 containsSomethingInteresting = true; 441 break; 442 } 443 case PathDiagnosticPiece::Macro: { 444 auto ¯o = cast<PathDiagnosticMacroPiece>(*piece); 445 if (!removeUnneededCalls(C, macro.subPieces, R, IsInteresting)) 446 continue; 447 containsSomethingInteresting = true; 448 break; 449 } 450 case PathDiagnosticPiece::Event: { 451 auto &event = cast<PathDiagnosticEventPiece>(*piece); 452 453 // We never throw away an event, but we do throw it away wholesale 454 // as part of a path if we throw the entire path away. 455 containsSomethingInteresting |= !event.isPrunable(); 456 break; 457 } 458 case PathDiagnosticPiece::ControlFlow: 459 case PathDiagnosticPiece::Note: 460 case PathDiagnosticPiece::PopUp: 461 break; 462 } 463 464 pieces.push_back(std::move(piece)); 465 } 466 467 return containsSomethingInteresting; 468 } 469 470 /// Same logic as above to remove extra pieces. 471 static void removePopUpNotes(PathPieces &Path) { 472 for (unsigned int i = 0; i < Path.size(); ++i) { 473 auto Piece = std::move(Path.front()); 474 Path.pop_front(); 475 if (!isa<PathDiagnosticPopUpPiece>(*Piece)) 476 Path.push_back(std::move(Piece)); 477 } 478 } 479 480 /// Returns true if the given decl has been implicitly given a body, either by 481 /// the analyzer or by the compiler proper. 482 static bool hasImplicitBody(const Decl *D) { 483 assert(D); 484 return D->isImplicit() || !D->hasBody(); 485 } 486 487 /// Recursively scan through a path and make sure that all call pieces have 488 /// valid locations. 489 static void 490 adjustCallLocations(PathPieces &Pieces, 491 PathDiagnosticLocation *LastCallLocation = nullptr) { 492 for (const auto &I : Pieces) { 493 auto *Call = dyn_cast<PathDiagnosticCallPiece>(I.get()); 494 495 if (!Call) 496 continue; 497 498 if (LastCallLocation) { 499 bool CallerIsImplicit = hasImplicitBody(Call->getCaller()); 500 if (CallerIsImplicit || !Call->callEnter.asLocation().isValid()) 501 Call->callEnter = *LastCallLocation; 502 if (CallerIsImplicit || !Call->callReturn.asLocation().isValid()) 503 Call->callReturn = *LastCallLocation; 504 } 505 506 // Recursively clean out the subclass. Keep this call around if 507 // it contains any informative diagnostics. 508 PathDiagnosticLocation *ThisCallLocation; 509 if (Call->callEnterWithin.asLocation().isValid() && 510 !hasImplicitBody(Call->getCallee())) 511 ThisCallLocation = &Call->callEnterWithin; 512 else 513 ThisCallLocation = &Call->callEnter; 514 515 assert(ThisCallLocation && "Outermost call has an invalid location"); 516 adjustCallLocations(Call->path, ThisCallLocation); 517 } 518 } 519 520 /// Remove edges in and out of C++ default initializer expressions. These are 521 /// for fields that have in-class initializers, as opposed to being initialized 522 /// explicitly in a constructor or braced list. 523 static void removeEdgesToDefaultInitializers(PathPieces &Pieces) { 524 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) { 525 if (auto *C = dyn_cast<PathDiagnosticCallPiece>(I->get())) 526 removeEdgesToDefaultInitializers(C->path); 527 528 if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(I->get())) 529 removeEdgesToDefaultInitializers(M->subPieces); 530 531 if (auto *CF = dyn_cast<PathDiagnosticControlFlowPiece>(I->get())) { 532 const Stmt *Start = CF->getStartLocation().asStmt(); 533 const Stmt *End = CF->getEndLocation().asStmt(); 534 if (Start && isa<CXXDefaultInitExpr>(Start)) { 535 I = Pieces.erase(I); 536 continue; 537 } else if (End && isa<CXXDefaultInitExpr>(End)) { 538 PathPieces::iterator Next = std::next(I); 539 if (Next != E) { 540 if (auto *NextCF = 541 dyn_cast<PathDiagnosticControlFlowPiece>(Next->get())) { 542 NextCF->setStartLocation(CF->getStartLocation()); 543 } 544 } 545 I = Pieces.erase(I); 546 continue; 547 } 548 } 549 550 I++; 551 } 552 } 553 554 /// Remove all pieces with invalid locations as these cannot be serialized. 555 /// We might have pieces with invalid locations as a result of inlining Body 556 /// Farm generated functions. 557 static void removePiecesWithInvalidLocations(PathPieces &Pieces) { 558 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) { 559 if (auto *C = dyn_cast<PathDiagnosticCallPiece>(I->get())) 560 removePiecesWithInvalidLocations(C->path); 561 562 if (auto *M = dyn_cast<PathDiagnosticMacroPiece>(I->get())) 563 removePiecesWithInvalidLocations(M->subPieces); 564 565 if (!(*I)->getLocation().isValid() || 566 !(*I)->getLocation().asLocation().isValid()) { 567 I = Pieces.erase(I); 568 continue; 569 } 570 I++; 571 } 572 } 573 574 PathDiagnosticLocation PathDiagnosticBuilder::ExecutionContinues( 575 const PathDiagnosticConstruct &C) const { 576 if (const Stmt *S = C.getCurrentNode()->getNextStmtForDiagnostics()) 577 return PathDiagnosticLocation(S, getSourceManager(), 578 C.getCurrLocationContext()); 579 580 return PathDiagnosticLocation::createDeclEnd(C.getCurrLocationContext(), 581 getSourceManager()); 582 } 583 584 PathDiagnosticLocation PathDiagnosticBuilder::ExecutionContinues( 585 llvm::raw_string_ostream &os, const PathDiagnosticConstruct &C) const { 586 // Slow, but probably doesn't matter. 587 if (os.str().empty()) 588 os << ' '; 589 590 const PathDiagnosticLocation &Loc = ExecutionContinues(C); 591 592 if (Loc.asStmt()) 593 os << "Execution continues on line " 594 << getSourceManager().getExpansionLineNumber(Loc.asLocation()) 595 << '.'; 596 else { 597 os << "Execution jumps to the end of the "; 598 const Decl *D = C.getCurrLocationContext()->getDecl(); 599 if (isa<ObjCMethodDecl>(D)) 600 os << "method"; 601 else if (isa<FunctionDecl>(D)) 602 os << "function"; 603 else { 604 assert(isa<BlockDecl>(D)); 605 os << "anonymous block"; 606 } 607 os << '.'; 608 } 609 610 return Loc; 611 } 612 613 static const Stmt *getEnclosingParent(const Stmt *S, const ParentMap &PM) { 614 if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S))) 615 return PM.getParentIgnoreParens(S); 616 617 const Stmt *Parent = PM.getParentIgnoreParens(S); 618 if (!Parent) 619 return nullptr; 620 621 switch (Parent->getStmtClass()) { 622 case Stmt::ForStmtClass: 623 case Stmt::DoStmtClass: 624 case Stmt::WhileStmtClass: 625 case Stmt::ObjCForCollectionStmtClass: 626 case Stmt::CXXForRangeStmtClass: 627 return Parent; 628 default: 629 break; 630 } 631 632 return nullptr; 633 } 634 635 static PathDiagnosticLocation 636 getEnclosingStmtLocation(const Stmt *S, const LocationContext *LC, 637 bool allowNestedContexts = false) { 638 if (!S) 639 return {}; 640 641 const SourceManager &SMgr = LC->getDecl()->getASTContext().getSourceManager(); 642 643 while (const Stmt *Parent = getEnclosingParent(S, LC->getParentMap())) { 644 switch (Parent->getStmtClass()) { 645 case Stmt::BinaryOperatorClass: { 646 const auto *B = cast<BinaryOperator>(Parent); 647 if (B->isLogicalOp()) 648 return PathDiagnosticLocation(allowNestedContexts ? B : S, SMgr, LC); 649 break; 650 } 651 case Stmt::CompoundStmtClass: 652 case Stmt::StmtExprClass: 653 return PathDiagnosticLocation(S, SMgr, LC); 654 case Stmt::ChooseExprClass: 655 // Similar to '?' if we are referring to condition, just have the edge 656 // point to the entire choose expression. 657 if (allowNestedContexts || cast<ChooseExpr>(Parent)->getCond() == S) 658 return PathDiagnosticLocation(Parent, SMgr, LC); 659 else 660 return PathDiagnosticLocation(S, SMgr, LC); 661 case Stmt::BinaryConditionalOperatorClass: 662 case Stmt::ConditionalOperatorClass: 663 // For '?', if we are referring to condition, just have the edge point 664 // to the entire '?' expression. 665 if (allowNestedContexts || 666 cast<AbstractConditionalOperator>(Parent)->getCond() == S) 667 return PathDiagnosticLocation(Parent, SMgr, LC); 668 else 669 return PathDiagnosticLocation(S, SMgr, LC); 670 case Stmt::CXXForRangeStmtClass: 671 if (cast<CXXForRangeStmt>(Parent)->getBody() == S) 672 return PathDiagnosticLocation(S, SMgr, LC); 673 break; 674 case Stmt::DoStmtClass: 675 return PathDiagnosticLocation(S, SMgr, LC); 676 case Stmt::ForStmtClass: 677 if (cast<ForStmt>(Parent)->getBody() == S) 678 return PathDiagnosticLocation(S, SMgr, LC); 679 break; 680 case Stmt::IfStmtClass: 681 if (cast<IfStmt>(Parent)->getCond() != S) 682 return PathDiagnosticLocation(S, SMgr, LC); 683 break; 684 case Stmt::ObjCForCollectionStmtClass: 685 if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S) 686 return PathDiagnosticLocation(S, SMgr, LC); 687 break; 688 case Stmt::WhileStmtClass: 689 if (cast<WhileStmt>(Parent)->getCond() != S) 690 return PathDiagnosticLocation(S, SMgr, LC); 691 break; 692 default: 693 break; 694 } 695 696 S = Parent; 697 } 698 699 assert(S && "Cannot have null Stmt for PathDiagnosticLocation"); 700 701 return PathDiagnosticLocation(S, SMgr, LC); 702 } 703 704 //===----------------------------------------------------------------------===// 705 // "Minimal" path diagnostic generation algorithm. 706 //===----------------------------------------------------------------------===// 707 708 /// If the piece contains a special message, add it to all the call pieces on 709 /// the active stack. For example, my_malloc allocated memory, so MallocChecker 710 /// will construct an event at the call to malloc(), and add a stack hint that 711 /// an allocated memory was returned. We'll use this hint to construct a message 712 /// when returning from the call to my_malloc 713 /// 714 /// void *my_malloc() { return malloc(sizeof(int)); } 715 /// void fishy() { 716 /// void *ptr = my_malloc(); // returned allocated memory 717 /// } // leak 718 void PathDiagnosticBuilder::updateStackPiecesWithMessage( 719 PathDiagnosticPieceRef P, const CallWithEntryStack &CallStack) const { 720 if (R->hasCallStackHint(P)) 721 for (const auto &I : CallStack) { 722 PathDiagnosticCallPiece *CP = I.first; 723 const ExplodedNode *N = I.second; 724 std::string stackMsg = R->getCallStackMessage(P, N); 725 726 // The last message on the path to final bug is the most important 727 // one. Since we traverse the path backwards, do not add the message 728 // if one has been previously added. 729 if (!CP->hasCallStackMessage()) 730 CP->setCallStackMessage(stackMsg); 731 } 732 } 733 734 static void CompactMacroExpandedPieces(PathPieces &path, 735 const SourceManager& SM); 736 737 PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForSwitchOP( 738 const PathDiagnosticConstruct &C, const CFGBlock *Dst, 739 PathDiagnosticLocation &Start) const { 740 741 const SourceManager &SM = getSourceManager(); 742 // Figure out what case arm we took. 743 std::string sbuf; 744 llvm::raw_string_ostream os(sbuf); 745 PathDiagnosticLocation End; 746 747 if (const Stmt *S = Dst->getLabel()) { 748 End = PathDiagnosticLocation(S, SM, C.getCurrLocationContext()); 749 750 switch (S->getStmtClass()) { 751 default: 752 os << "No cases match in the switch statement. " 753 "Control jumps to line " 754 << End.asLocation().getExpansionLineNumber(); 755 break; 756 case Stmt::DefaultStmtClass: 757 os << "Control jumps to the 'default' case at line " 758 << End.asLocation().getExpansionLineNumber(); 759 break; 760 761 case Stmt::CaseStmtClass: { 762 os << "Control jumps to 'case "; 763 const auto *Case = cast<CaseStmt>(S); 764 const Expr *LHS = Case->getLHS()->IgnoreParenCasts(); 765 766 // Determine if it is an enum. 767 bool GetRawInt = true; 768 769 if (const auto *DR = dyn_cast<DeclRefExpr>(LHS)) { 770 // FIXME: Maybe this should be an assertion. Are there cases 771 // were it is not an EnumConstantDecl? 772 const auto *D = dyn_cast<EnumConstantDecl>(DR->getDecl()); 773 774 if (D) { 775 GetRawInt = false; 776 os << *D; 777 } 778 } 779 780 if (GetRawInt) 781 os << LHS->EvaluateKnownConstInt(getASTContext()); 782 783 os << ":' at line " << End.asLocation().getExpansionLineNumber(); 784 break; 785 } 786 } 787 } else { 788 os << "'Default' branch taken. "; 789 End = ExecutionContinues(os, C); 790 } 791 return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, 792 os.str()); 793 } 794 795 PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForGotoOP( 796 const PathDiagnosticConstruct &C, const Stmt *S, 797 PathDiagnosticLocation &Start) const { 798 std::string sbuf; 799 llvm::raw_string_ostream os(sbuf); 800 const PathDiagnosticLocation &End = 801 getEnclosingStmtLocation(S, C.getCurrLocationContext()); 802 os << "Control jumps to line " << End.asLocation().getExpansionLineNumber(); 803 return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str()); 804 } 805 806 PathDiagnosticPieceRef PathDiagnosticBuilder::generateDiagForBinaryOP( 807 const PathDiagnosticConstruct &C, const Stmt *T, const CFGBlock *Src, 808 const CFGBlock *Dst) const { 809 810 const SourceManager &SM = getSourceManager(); 811 812 const auto *B = cast<BinaryOperator>(T); 813 std::string sbuf; 814 llvm::raw_string_ostream os(sbuf); 815 os << "Left side of '"; 816 PathDiagnosticLocation Start, End; 817 818 if (B->getOpcode() == BO_LAnd) { 819 os << "&&" 820 << "' is "; 821 822 if (*(Src->succ_begin() + 1) == Dst) { 823 os << "false"; 824 End = PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext()); 825 Start = 826 PathDiagnosticLocation::createOperatorLoc(B, SM); 827 } else { 828 os << "true"; 829 Start = 830 PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext()); 831 End = ExecutionContinues(C); 832 } 833 } else { 834 assert(B->getOpcode() == BO_LOr); 835 os << "||" 836 << "' is "; 837 838 if (*(Src->succ_begin() + 1) == Dst) { 839 os << "false"; 840 Start = 841 PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext()); 842 End = ExecutionContinues(C); 843 } else { 844 os << "true"; 845 End = PathDiagnosticLocation(B->getLHS(), SM, C.getCurrLocationContext()); 846 Start = 847 PathDiagnosticLocation::createOperatorLoc(B, SM); 848 } 849 } 850 return std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, 851 os.str()); 852 } 853 854 void PathDiagnosticBuilder::generateMinimalDiagForBlockEdge( 855 PathDiagnosticConstruct &C, BlockEdge BE) const { 856 const SourceManager &SM = getSourceManager(); 857 const LocationContext *LC = C.getCurrLocationContext(); 858 const CFGBlock *Src = BE.getSrc(); 859 const CFGBlock *Dst = BE.getDst(); 860 const Stmt *T = Src->getTerminatorStmt(); 861 if (!T) 862 return; 863 864 auto Start = PathDiagnosticLocation::createBegin(T, SM, LC); 865 switch (T->getStmtClass()) { 866 default: 867 break; 868 869 case Stmt::GotoStmtClass: 870 case Stmt::IndirectGotoStmtClass: { 871 if (const Stmt *S = C.getCurrentNode()->getNextStmtForDiagnostics()) 872 C.getActivePath().push_front(generateDiagForGotoOP(C, S, Start)); 873 break; 874 } 875 876 case Stmt::SwitchStmtClass: { 877 C.getActivePath().push_front(generateDiagForSwitchOP(C, Dst, Start)); 878 break; 879 } 880 881 case Stmt::BreakStmtClass: 882 case Stmt::ContinueStmtClass: { 883 std::string sbuf; 884 llvm::raw_string_ostream os(sbuf); 885 PathDiagnosticLocation End = ExecutionContinues(os, C); 886 C.getActivePath().push_front( 887 std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str())); 888 break; 889 } 890 891 // Determine control-flow for ternary '?'. 892 case Stmt::BinaryConditionalOperatorClass: 893 case Stmt::ConditionalOperatorClass: { 894 std::string sbuf; 895 llvm::raw_string_ostream os(sbuf); 896 os << "'?' condition is "; 897 898 if (*(Src->succ_begin() + 1) == Dst) 899 os << "false"; 900 else 901 os << "true"; 902 903 PathDiagnosticLocation End = ExecutionContinues(C); 904 905 if (const Stmt *S = End.asStmt()) 906 End = getEnclosingStmtLocation(S, C.getCurrLocationContext()); 907 908 C.getActivePath().push_front( 909 std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, os.str())); 910 break; 911 } 912 913 // Determine control-flow for short-circuited '&&' and '||'. 914 case Stmt::BinaryOperatorClass: { 915 if (!C.supportsLogicalOpControlFlow()) 916 break; 917 918 C.getActivePath().push_front(generateDiagForBinaryOP(C, T, Src, Dst)); 919 break; 920 } 921 922 case Stmt::DoStmtClass: 923 if (*(Src->succ_begin()) == Dst) { 924 std::string sbuf; 925 llvm::raw_string_ostream os(sbuf); 926 927 os << "Loop condition is true. "; 928 PathDiagnosticLocation End = ExecutionContinues(os, C); 929 930 if (const Stmt *S = End.asStmt()) 931 End = getEnclosingStmtLocation(S, C.getCurrLocationContext()); 932 933 C.getActivePath().push_front( 934 std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, 935 os.str())); 936 } else { 937 PathDiagnosticLocation End = ExecutionContinues(C); 938 939 if (const Stmt *S = End.asStmt()) 940 End = getEnclosingStmtLocation(S, C.getCurrLocationContext()); 941 942 C.getActivePath().push_front( 943 std::make_shared<PathDiagnosticControlFlowPiece>( 944 Start, End, "Loop condition is false. Exiting loop")); 945 } 946 break; 947 948 case Stmt::WhileStmtClass: 949 case Stmt::ForStmtClass: 950 if (*(Src->succ_begin() + 1) == Dst) { 951 std::string sbuf; 952 llvm::raw_string_ostream os(sbuf); 953 954 os << "Loop condition is false. "; 955 PathDiagnosticLocation End = ExecutionContinues(os, C); 956 if (const Stmt *S = End.asStmt()) 957 End = getEnclosingStmtLocation(S, C.getCurrLocationContext()); 958 959 C.getActivePath().push_front( 960 std::make_shared<PathDiagnosticControlFlowPiece>(Start, End, 961 os.str())); 962 } else { 963 PathDiagnosticLocation End = ExecutionContinues(C); 964 if (const Stmt *S = End.asStmt()) 965 End = getEnclosingStmtLocation(S, C.getCurrLocationContext()); 966 967 C.getActivePath().push_front( 968 std::make_shared<PathDiagnosticControlFlowPiece>( 969 Start, End, "Loop condition is true. Entering loop body")); 970 } 971 972 break; 973 974 case Stmt::IfStmtClass: { 975 PathDiagnosticLocation End = ExecutionContinues(C); 976 977 if (const Stmt *S = End.asStmt()) 978 End = getEnclosingStmtLocation(S, C.getCurrLocationContext()); 979 980 if (*(Src->succ_begin() + 1) == Dst) 981 C.getActivePath().push_front( 982 std::make_shared<PathDiagnosticControlFlowPiece>( 983 Start, End, "Taking false branch")); 984 else 985 C.getActivePath().push_front( 986 std::make_shared<PathDiagnosticControlFlowPiece>( 987 Start, End, "Taking true branch")); 988 989 break; 990 } 991 } 992 } 993 994 //===----------------------------------------------------------------------===// 995 // Functions for determining if a loop was executed 0 times. 996 //===----------------------------------------------------------------------===// 997 998 static bool isLoop(const Stmt *Term) { 999 switch (Term->getStmtClass()) { 1000 case Stmt::ForStmtClass: 1001 case Stmt::WhileStmtClass: 1002 case Stmt::ObjCForCollectionStmtClass: 1003 case Stmt::CXXForRangeStmtClass: 1004 return true; 1005 default: 1006 // Note that we intentionally do not include do..while here. 1007 return false; 1008 } 1009 } 1010 1011 static bool isJumpToFalseBranch(const BlockEdge *BE) { 1012 const CFGBlock *Src = BE->getSrc(); 1013 assert(Src->succ_size() == 2); 1014 return (*(Src->succ_begin()+1) == BE->getDst()); 1015 } 1016 1017 static bool isContainedByStmt(const ParentMap &PM, const Stmt *S, 1018 const Stmt *SubS) { 1019 while (SubS) { 1020 if (SubS == S) 1021 return true; 1022 SubS = PM.getParent(SubS); 1023 } 1024 return false; 1025 } 1026 1027 static const Stmt *getStmtBeforeCond(const ParentMap &PM, const Stmt *Term, 1028 const ExplodedNode *N) { 1029 while (N) { 1030 Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>(); 1031 if (SP) { 1032 const Stmt *S = SP->getStmt(); 1033 if (!isContainedByStmt(PM, Term, S)) 1034 return S; 1035 } 1036 N = N->getFirstPred(); 1037 } 1038 return nullptr; 1039 } 1040 1041 static bool isInLoopBody(const ParentMap &PM, const Stmt *S, const Stmt *Term) { 1042 const Stmt *LoopBody = nullptr; 1043 switch (Term->getStmtClass()) { 1044 case Stmt::CXXForRangeStmtClass: { 1045 const auto *FR = cast<CXXForRangeStmt>(Term); 1046 if (isContainedByStmt(PM, FR->getInc(), S)) 1047 return true; 1048 if (isContainedByStmt(PM, FR->getLoopVarStmt(), S)) 1049 return true; 1050 LoopBody = FR->getBody(); 1051 break; 1052 } 1053 case Stmt::ForStmtClass: { 1054 const auto *FS = cast<ForStmt>(Term); 1055 if (isContainedByStmt(PM, FS->getInc(), S)) 1056 return true; 1057 LoopBody = FS->getBody(); 1058 break; 1059 } 1060 case Stmt::ObjCForCollectionStmtClass: { 1061 const auto *FC = cast<ObjCForCollectionStmt>(Term); 1062 LoopBody = FC->getBody(); 1063 break; 1064 } 1065 case Stmt::WhileStmtClass: 1066 LoopBody = cast<WhileStmt>(Term)->getBody(); 1067 break; 1068 default: 1069 return false; 1070 } 1071 return isContainedByStmt(PM, LoopBody, S); 1072 } 1073 1074 /// Adds a sanitized control-flow diagnostic edge to a path. 1075 static void addEdgeToPath(PathPieces &path, 1076 PathDiagnosticLocation &PrevLoc, 1077 PathDiagnosticLocation NewLoc) { 1078 if (!NewLoc.isValid()) 1079 return; 1080 1081 SourceLocation NewLocL = NewLoc.asLocation(); 1082 if (NewLocL.isInvalid()) 1083 return; 1084 1085 if (!PrevLoc.isValid() || !PrevLoc.asLocation().isValid()) { 1086 PrevLoc = NewLoc; 1087 return; 1088 } 1089 1090 // Ignore self-edges, which occur when there are multiple nodes at the same 1091 // statement. 1092 if (NewLoc.asStmt() && NewLoc.asStmt() == PrevLoc.asStmt()) 1093 return; 1094 1095 path.push_front( 1096 std::make_shared<PathDiagnosticControlFlowPiece>(NewLoc, PrevLoc)); 1097 PrevLoc = NewLoc; 1098 } 1099 1100 /// A customized wrapper for CFGBlock::getTerminatorCondition() 1101 /// which returns the element for ObjCForCollectionStmts. 1102 static const Stmt *getTerminatorCondition(const CFGBlock *B) { 1103 const Stmt *S = B->getTerminatorCondition(); 1104 if (const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(S)) 1105 return FS->getElement(); 1106 return S; 1107 } 1108 1109 constexpr llvm::StringLiteral StrEnteringLoop = "Entering loop body"; 1110 constexpr llvm::StringLiteral StrLoopBodyZero = "Loop body executed 0 times"; 1111 constexpr llvm::StringLiteral StrLoopRangeEmpty = 1112 "Loop body skipped when range is empty"; 1113 constexpr llvm::StringLiteral StrLoopCollectionEmpty = 1114 "Loop body skipped when collection is empty"; 1115 1116 static std::unique_ptr<FilesToLineNumsMap> 1117 findExecutedLines(const SourceManager &SM, const ExplodedNode *N); 1118 1119 void PathDiagnosticBuilder::generatePathDiagnosticsForNode( 1120 PathDiagnosticConstruct &C, PathDiagnosticLocation &PrevLoc) const { 1121 ProgramPoint P = C.getCurrentNode()->getLocation(); 1122 const SourceManager &SM = getSourceManager(); 1123 1124 // Have we encountered an entrance to a call? It may be 1125 // the case that we have not encountered a matching 1126 // call exit before this point. This means that the path 1127 // terminated within the call itself. 1128 if (auto CE = P.getAs<CallEnter>()) { 1129 1130 if (C.shouldAddPathEdges()) { 1131 // Add an edge to the start of the function. 1132 const StackFrameContext *CalleeLC = CE->getCalleeContext(); 1133 const Decl *D = CalleeLC->getDecl(); 1134 // Add the edge only when the callee has body. We jump to the beginning 1135 // of the *declaration*, however we expect it to be followed by the 1136 // body. This isn't the case for autosynthesized property accessors in 1137 // Objective-C. No need for a similar extra check for CallExit points 1138 // because the exit edge comes from a statement (i.e. return), 1139 // not from declaration. 1140 if (D->hasBody()) 1141 addEdgeToPath(C.getActivePath(), PrevLoc, 1142 PathDiagnosticLocation::createBegin(D, SM)); 1143 } 1144 1145 // Did we visit an entire call? 1146 bool VisitedEntireCall = C.PD->isWithinCall(); 1147 C.PD->popActivePath(); 1148 1149 PathDiagnosticCallPiece *Call; 1150 if (VisitedEntireCall) { 1151 Call = cast<PathDiagnosticCallPiece>(C.getActivePath().front().get()); 1152 } else { 1153 // The path terminated within a nested location context, create a new 1154 // call piece to encapsulate the rest of the path pieces. 1155 const Decl *Caller = CE->getLocationContext()->getDecl(); 1156 Call = PathDiagnosticCallPiece::construct(C.getActivePath(), Caller); 1157 assert(C.getActivePath().size() == 1 && 1158 C.getActivePath().front().get() == Call); 1159 1160 // Since we just transferred the path over to the call piece, reset the 1161 // mapping of the active path to the current location context. 1162 assert(C.isInLocCtxMap(&C.getActivePath()) && 1163 "When we ascend to a previously unvisited call, the active path's " 1164 "address shouldn't change, but rather should be compacted into " 1165 "a single CallEvent!"); 1166 C.updateLocCtxMap(&C.getActivePath(), C.getCurrLocationContext()); 1167 1168 // Record the location context mapping for the path within the call. 1169 assert(!C.isInLocCtxMap(&Call->path) && 1170 "When we ascend to a previously unvisited call, this must be the " 1171 "first time we encounter the caller context!"); 1172 C.updateLocCtxMap(&Call->path, CE->getCalleeContext()); 1173 } 1174 Call->setCallee(*CE, SM); 1175 1176 // Update the previous location in the active path. 1177 PrevLoc = Call->getLocation(); 1178 1179 if (!C.CallStack.empty()) { 1180 assert(C.CallStack.back().first == Call); 1181 C.CallStack.pop_back(); 1182 } 1183 return; 1184 } 1185 1186 assert(C.getCurrLocationContext() == C.getLocationContextForActivePath() && 1187 "The current position in the bug path is out of sync with the " 1188 "location context associated with the active path!"); 1189 1190 // Have we encountered an exit from a function call? 1191 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1192 1193 // We are descending into a call (backwards). Construct 1194 // a new call piece to contain the path pieces for that call. 1195 auto Call = PathDiagnosticCallPiece::construct(*CE, SM); 1196 // Record the mapping from call piece to LocationContext. 1197 assert(!C.isInLocCtxMap(&Call->path) && 1198 "We just entered a call, this must've been the first time we " 1199 "encounter its context!"); 1200 C.updateLocCtxMap(&Call->path, CE->getCalleeContext()); 1201 1202 if (C.shouldAddPathEdges()) { 1203 // Add the edge to the return site. 1204 addEdgeToPath(C.getActivePath(), PrevLoc, Call->callReturn); 1205 PrevLoc.invalidate(); 1206 } 1207 1208 auto *P = Call.get(); 1209 C.getActivePath().push_front(std::move(Call)); 1210 1211 // Make the contents of the call the active path for now. 1212 C.PD->pushActivePath(&P->path); 1213 C.CallStack.push_back(CallWithEntry(P, C.getCurrentNode())); 1214 return; 1215 } 1216 1217 if (auto PS = P.getAs<PostStmt>()) { 1218 if (!C.shouldAddPathEdges()) 1219 return; 1220 1221 // Add an edge. If this is an ObjCForCollectionStmt do 1222 // not add an edge here as it appears in the CFG both 1223 // as a terminator and as a terminator condition. 1224 if (!isa<ObjCForCollectionStmt>(PS->getStmt())) { 1225 PathDiagnosticLocation L = 1226 PathDiagnosticLocation(PS->getStmt(), SM, C.getCurrLocationContext()); 1227 addEdgeToPath(C.getActivePath(), PrevLoc, L); 1228 } 1229 1230 } else if (auto BE = P.getAs<BlockEdge>()) { 1231 1232 if (!C.shouldAddPathEdges()) { 1233 generateMinimalDiagForBlockEdge(C, *BE); 1234 return; 1235 } 1236 1237 // Are we jumping to the head of a loop? Add a special diagnostic. 1238 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1239 PathDiagnosticLocation L(Loop, SM, C.getCurrLocationContext()); 1240 const Stmt *Body = nullptr; 1241 1242 if (const auto *FS = dyn_cast<ForStmt>(Loop)) 1243 Body = FS->getBody(); 1244 else if (const auto *WS = dyn_cast<WhileStmt>(Loop)) 1245 Body = WS->getBody(); 1246 else if (const auto *OFS = dyn_cast<ObjCForCollectionStmt>(Loop)) { 1247 Body = OFS->getBody(); 1248 } else if (const auto *FRS = dyn_cast<CXXForRangeStmt>(Loop)) { 1249 Body = FRS->getBody(); 1250 } 1251 // do-while statements are explicitly excluded here 1252 1253 auto p = std::make_shared<PathDiagnosticEventPiece>( 1254 L, "Looping back to the head " 1255 "of the loop"); 1256 p->setPrunable(true); 1257 1258 addEdgeToPath(C.getActivePath(), PrevLoc, p->getLocation()); 1259 C.getActivePath().push_front(std::move(p)); 1260 1261 if (const auto *CS = dyn_cast_or_null<CompoundStmt>(Body)) { 1262 addEdgeToPath(C.getActivePath(), PrevLoc, 1263 PathDiagnosticLocation::createEndBrace(CS, SM)); 1264 } 1265 } 1266 1267 const CFGBlock *BSrc = BE->getSrc(); 1268 const ParentMap &PM = C.getParentMap(); 1269 1270 if (const Stmt *Term = BSrc->getTerminatorStmt()) { 1271 // Are we jumping past the loop body without ever executing the 1272 // loop (because the condition was false)? 1273 if (isLoop(Term)) { 1274 const Stmt *TermCond = getTerminatorCondition(BSrc); 1275 bool IsInLoopBody = isInLoopBody( 1276 PM, getStmtBeforeCond(PM, TermCond, C.getCurrentNode()), Term); 1277 1278 StringRef str; 1279 1280 if (isJumpToFalseBranch(&*BE)) { 1281 if (!IsInLoopBody) { 1282 if (isa<ObjCForCollectionStmt>(Term)) { 1283 str = StrLoopCollectionEmpty; 1284 } else if (isa<CXXForRangeStmt>(Term)) { 1285 str = StrLoopRangeEmpty; 1286 } else { 1287 str = StrLoopBodyZero; 1288 } 1289 } 1290 } else { 1291 str = StrEnteringLoop; 1292 } 1293 1294 if (!str.empty()) { 1295 PathDiagnosticLocation L(TermCond ? TermCond : Term, SM, 1296 C.getCurrLocationContext()); 1297 auto PE = std::make_shared<PathDiagnosticEventPiece>(L, str); 1298 PE->setPrunable(true); 1299 addEdgeToPath(C.getActivePath(), PrevLoc, PE->getLocation()); 1300 C.getActivePath().push_front(std::move(PE)); 1301 } 1302 } else if (isa<BreakStmt>(Term) || isa<ContinueStmt>(Term) || 1303 isa<GotoStmt>(Term)) { 1304 PathDiagnosticLocation L(Term, SM, C.getCurrLocationContext()); 1305 addEdgeToPath(C.getActivePath(), PrevLoc, L); 1306 } 1307 } 1308 } 1309 } 1310 1311 static std::unique_ptr<PathDiagnostic> 1312 generateDiagnosticForBasicReport(const BasicBugReport *R) { 1313 const BugType &BT = R->getBugType(); 1314 return std::make_unique<PathDiagnostic>( 1315 BT.getCheckerName(), R->getDeclWithIssue(), BT.getDescription(), 1316 R->getDescription(), R->getShortDescription(/*UseFallback=*/false), 1317 BT.getCategory(), R->getUniqueingLocation(), R->getUniqueingDecl(), 1318 std::make_unique<FilesToLineNumsMap>()); 1319 } 1320 1321 static std::unique_ptr<PathDiagnostic> 1322 generateEmptyDiagnosticForReport(const PathSensitiveBugReport *R, 1323 const SourceManager &SM) { 1324 const BugType &BT = R->getBugType(); 1325 return std::make_unique<PathDiagnostic>( 1326 BT.getCheckerName(), R->getDeclWithIssue(), BT.getDescription(), 1327 R->getDescription(), R->getShortDescription(/*UseFallback=*/false), 1328 BT.getCategory(), R->getUniqueingLocation(), R->getUniqueingDecl(), 1329 findExecutedLines(SM, R->getErrorNode())); 1330 } 1331 1332 static const Stmt *getStmtParent(const Stmt *S, const ParentMap &PM) { 1333 if (!S) 1334 return nullptr; 1335 1336 while (true) { 1337 S = PM.getParentIgnoreParens(S); 1338 1339 if (!S) 1340 break; 1341 1342 if (isa<FullExpr>(S) || 1343 isa<CXXBindTemporaryExpr>(S) || 1344 isa<SubstNonTypeTemplateParmExpr>(S)) 1345 continue; 1346 1347 break; 1348 } 1349 1350 return S; 1351 } 1352 1353 static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) { 1354 switch (S->getStmtClass()) { 1355 case Stmt::BinaryOperatorClass: { 1356 const auto *BO = cast<BinaryOperator>(S); 1357 if (!BO->isLogicalOp()) 1358 return false; 1359 return BO->getLHS() == Cond || BO->getRHS() == Cond; 1360 } 1361 case Stmt::IfStmtClass: 1362 return cast<IfStmt>(S)->getCond() == Cond; 1363 case Stmt::ForStmtClass: 1364 return cast<ForStmt>(S)->getCond() == Cond; 1365 case Stmt::WhileStmtClass: 1366 return cast<WhileStmt>(S)->getCond() == Cond; 1367 case Stmt::DoStmtClass: 1368 return cast<DoStmt>(S)->getCond() == Cond; 1369 case Stmt::ChooseExprClass: 1370 return cast<ChooseExpr>(S)->getCond() == Cond; 1371 case Stmt::IndirectGotoStmtClass: 1372 return cast<IndirectGotoStmt>(S)->getTarget() == Cond; 1373 case Stmt::SwitchStmtClass: 1374 return cast<SwitchStmt>(S)->getCond() == Cond; 1375 case Stmt::BinaryConditionalOperatorClass: 1376 return cast<BinaryConditionalOperator>(S)->getCond() == Cond; 1377 case Stmt::ConditionalOperatorClass: { 1378 const auto *CO = cast<ConditionalOperator>(S); 1379 return CO->getCond() == Cond || 1380 CO->getLHS() == Cond || 1381 CO->getRHS() == Cond; 1382 } 1383 case Stmt::ObjCForCollectionStmtClass: 1384 return cast<ObjCForCollectionStmt>(S)->getElement() == Cond; 1385 case Stmt::CXXForRangeStmtClass: { 1386 const auto *FRS = cast<CXXForRangeStmt>(S); 1387 return FRS->getCond() == Cond || FRS->getRangeInit() == Cond; 1388 } 1389 default: 1390 return false; 1391 } 1392 } 1393 1394 static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) { 1395 if (const auto *FS = dyn_cast<ForStmt>(FL)) 1396 return FS->getInc() == S || FS->getInit() == S; 1397 if (const auto *FRS = dyn_cast<CXXForRangeStmt>(FL)) 1398 return FRS->getInc() == S || FRS->getRangeStmt() == S || 1399 FRS->getLoopVarStmt() || FRS->getRangeInit() == S; 1400 return false; 1401 } 1402 1403 using OptimizedCallsSet = llvm::DenseSet<const PathDiagnosticCallPiece *>; 1404 1405 /// Adds synthetic edges from top-level statements to their subexpressions. 1406 /// 1407 /// This avoids a "swoosh" effect, where an edge from a top-level statement A 1408 /// points to a sub-expression B.1 that's not at the start of B. In these cases, 1409 /// we'd like to see an edge from A to B, then another one from B to B.1. 1410 static void addContextEdges(PathPieces &pieces, const LocationContext *LC) { 1411 const ParentMap &PM = LC->getParentMap(); 1412 PathPieces::iterator Prev = pieces.end(); 1413 for (PathPieces::iterator I = pieces.begin(), E = Prev; I != E; 1414 Prev = I, ++I) { 1415 auto *Piece = dyn_cast<PathDiagnosticControlFlowPiece>(I->get()); 1416 1417 if (!Piece) 1418 continue; 1419 1420 PathDiagnosticLocation SrcLoc = Piece->getStartLocation(); 1421 SmallVector<PathDiagnosticLocation, 4> SrcContexts; 1422 1423 PathDiagnosticLocation NextSrcContext = SrcLoc; 1424 const Stmt *InnerStmt = nullptr; 1425 while (NextSrcContext.isValid() && NextSrcContext.asStmt() != InnerStmt) { 1426 SrcContexts.push_back(NextSrcContext); 1427 InnerStmt = NextSrcContext.asStmt(); 1428 NextSrcContext = getEnclosingStmtLocation(InnerStmt, LC, 1429 /*allowNested=*/true); 1430 } 1431 1432 // Repeatedly split the edge as necessary. 1433 // This is important for nested logical expressions (||, &&, ?:) where we 1434 // want to show all the levels of context. 1435 while (true) { 1436 const Stmt *Dst = Piece->getEndLocation().getStmtOrNull(); 1437 1438 // We are looking at an edge. Is the destination within a larger 1439 // expression? 1440 PathDiagnosticLocation DstContext = 1441 getEnclosingStmtLocation(Dst, LC, /*allowNested=*/true); 1442 if (!DstContext.isValid() || DstContext.asStmt() == Dst) 1443 break; 1444 1445 // If the source is in the same context, we're already good. 1446 if (llvm::find(SrcContexts, DstContext) != SrcContexts.end()) 1447 break; 1448 1449 // Update the subexpression node to point to the context edge. 1450 Piece->setStartLocation(DstContext); 1451 1452 // Try to extend the previous edge if it's at the same level as the source 1453 // context. 1454 if (Prev != E) { 1455 auto *PrevPiece = dyn_cast<PathDiagnosticControlFlowPiece>(Prev->get()); 1456 1457 if (PrevPiece) { 1458 if (const Stmt *PrevSrc = 1459 PrevPiece->getStartLocation().getStmtOrNull()) { 1460 const Stmt *PrevSrcParent = getStmtParent(PrevSrc, PM); 1461 if (PrevSrcParent == 1462 getStmtParent(DstContext.getStmtOrNull(), PM)) { 1463 PrevPiece->setEndLocation(DstContext); 1464 break; 1465 } 1466 } 1467 } 1468 } 1469 1470 // Otherwise, split the current edge into a context edge and a 1471 // subexpression edge. Note that the context statement may itself have 1472 // context. 1473 auto P = 1474 std::make_shared<PathDiagnosticControlFlowPiece>(SrcLoc, DstContext); 1475 Piece = P.get(); 1476 I = pieces.insert(I, std::move(P)); 1477 } 1478 } 1479 } 1480 1481 /// Move edges from a branch condition to a branch target 1482 /// when the condition is simple. 1483 /// 1484 /// This restructures some of the work of addContextEdges. That function 1485 /// creates edges this may destroy, but they work together to create a more 1486 /// aesthetically set of edges around branches. After the call to 1487 /// addContextEdges, we may have (1) an edge to the branch, (2) an edge from 1488 /// the branch to the branch condition, and (3) an edge from the branch 1489 /// condition to the branch target. We keep (1), but may wish to remove (2) 1490 /// and move the source of (3) to the branch if the branch condition is simple. 1491 static void simplifySimpleBranches(PathPieces &pieces) { 1492 for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; ++I) { 1493 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get()); 1494 1495 if (!PieceI) 1496 continue; 1497 1498 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull(); 1499 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull(); 1500 1501 if (!s1Start || !s1End) 1502 continue; 1503 1504 PathPieces::iterator NextI = I; ++NextI; 1505 if (NextI == E) 1506 break; 1507 1508 PathDiagnosticControlFlowPiece *PieceNextI = nullptr; 1509 1510 while (true) { 1511 if (NextI == E) 1512 break; 1513 1514 const auto *EV = dyn_cast<PathDiagnosticEventPiece>(NextI->get()); 1515 if (EV) { 1516 StringRef S = EV->getString(); 1517 if (S == StrEnteringLoop || S == StrLoopBodyZero || 1518 S == StrLoopCollectionEmpty || S == StrLoopRangeEmpty) { 1519 ++NextI; 1520 continue; 1521 } 1522 break; 1523 } 1524 1525 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get()); 1526 break; 1527 } 1528 1529 if (!PieceNextI) 1530 continue; 1531 1532 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull(); 1533 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull(); 1534 1535 if (!s2Start || !s2End || s1End != s2Start) 1536 continue; 1537 1538 // We only perform this transformation for specific branch kinds. 1539 // We don't want to do this for do..while, for example. 1540 if (!(isa<ForStmt>(s1Start) || isa<WhileStmt>(s1Start) || 1541 isa<IfStmt>(s1Start) || isa<ObjCForCollectionStmt>(s1Start) || 1542 isa<CXXForRangeStmt>(s1Start))) 1543 continue; 1544 1545 // Is s1End the branch condition? 1546 if (!isConditionForTerminator(s1Start, s1End)) 1547 continue; 1548 1549 // Perform the hoisting by eliminating (2) and changing the start 1550 // location of (3). 1551 PieceNextI->setStartLocation(PieceI->getStartLocation()); 1552 I = pieces.erase(I); 1553 } 1554 } 1555 1556 /// Returns the number of bytes in the given (character-based) SourceRange. 1557 /// 1558 /// If the locations in the range are not on the same line, returns None. 1559 /// 1560 /// Note that this does not do a precise user-visible character or column count. 1561 static Optional<size_t> getLengthOnSingleLine(const SourceManager &SM, 1562 SourceRange Range) { 1563 SourceRange ExpansionRange(SM.getExpansionLoc(Range.getBegin()), 1564 SM.getExpansionRange(Range.getEnd()).getEnd()); 1565 1566 FileID FID = SM.getFileID(ExpansionRange.getBegin()); 1567 if (FID != SM.getFileID(ExpansionRange.getEnd())) 1568 return None; 1569 1570 bool Invalid; 1571 const llvm::MemoryBuffer *Buffer = SM.getBuffer(FID, &Invalid); 1572 if (Invalid) 1573 return None; 1574 1575 unsigned BeginOffset = SM.getFileOffset(ExpansionRange.getBegin()); 1576 unsigned EndOffset = SM.getFileOffset(ExpansionRange.getEnd()); 1577 StringRef Snippet = Buffer->getBuffer().slice(BeginOffset, EndOffset); 1578 1579 // We're searching the raw bytes of the buffer here, which might include 1580 // escaped newlines and such. That's okay; we're trying to decide whether the 1581 // SourceRange is covering a large or small amount of space in the user's 1582 // editor. 1583 if (Snippet.find_first_of("\r\n") != StringRef::npos) 1584 return None; 1585 1586 // This isn't Unicode-aware, but it doesn't need to be. 1587 return Snippet.size(); 1588 } 1589 1590 /// \sa getLengthOnSingleLine(SourceManager, SourceRange) 1591 static Optional<size_t> getLengthOnSingleLine(const SourceManager &SM, 1592 const Stmt *S) { 1593 return getLengthOnSingleLine(SM, S->getSourceRange()); 1594 } 1595 1596 /// Eliminate two-edge cycles created by addContextEdges(). 1597 /// 1598 /// Once all the context edges are in place, there are plenty of cases where 1599 /// there's a single edge from a top-level statement to a subexpression, 1600 /// followed by a single path note, and then a reverse edge to get back out to 1601 /// the top level. If the statement is simple enough, the subexpression edges 1602 /// just add noise and make it harder to understand what's going on. 1603 /// 1604 /// This function only removes edges in pairs, because removing only one edge 1605 /// might leave other edges dangling. 1606 /// 1607 /// This will not remove edges in more complicated situations: 1608 /// - if there is more than one "hop" leading to or from a subexpression. 1609 /// - if there is an inlined call between the edges instead of a single event. 1610 /// - if the whole statement is large enough that having subexpression arrows 1611 /// might be helpful. 1612 static void removeContextCycles(PathPieces &Path, const SourceManager &SM) { 1613 for (PathPieces::iterator I = Path.begin(), E = Path.end(); I != E; ) { 1614 // Pattern match the current piece and its successor. 1615 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get()); 1616 1617 if (!PieceI) { 1618 ++I; 1619 continue; 1620 } 1621 1622 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull(); 1623 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull(); 1624 1625 PathPieces::iterator NextI = I; ++NextI; 1626 if (NextI == E) 1627 break; 1628 1629 const auto *PieceNextI = 1630 dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get()); 1631 1632 if (!PieceNextI) { 1633 if (isa<PathDiagnosticEventPiece>(NextI->get())) { 1634 ++NextI; 1635 if (NextI == E) 1636 break; 1637 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get()); 1638 } 1639 1640 if (!PieceNextI) { 1641 ++I; 1642 continue; 1643 } 1644 } 1645 1646 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull(); 1647 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull(); 1648 1649 if (s1Start && s2Start && s1Start == s2End && s2Start == s1End) { 1650 const size_t MAX_SHORT_LINE_LENGTH = 80; 1651 Optional<size_t> s1Length = getLengthOnSingleLine(SM, s1Start); 1652 if (s1Length && *s1Length <= MAX_SHORT_LINE_LENGTH) { 1653 Optional<size_t> s2Length = getLengthOnSingleLine(SM, s2Start); 1654 if (s2Length && *s2Length <= MAX_SHORT_LINE_LENGTH) { 1655 Path.erase(I); 1656 I = Path.erase(NextI); 1657 continue; 1658 } 1659 } 1660 } 1661 1662 ++I; 1663 } 1664 } 1665 1666 /// Return true if X is contained by Y. 1667 static bool lexicalContains(const ParentMap &PM, const Stmt *X, const Stmt *Y) { 1668 while (X) { 1669 if (X == Y) 1670 return true; 1671 X = PM.getParent(X); 1672 } 1673 return false; 1674 } 1675 1676 // Remove short edges on the same line less than 3 columns in difference. 1677 static void removePunyEdges(PathPieces &path, const SourceManager &SM, 1678 const ParentMap &PM) { 1679 bool erased = false; 1680 1681 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; 1682 erased ? I : ++I) { 1683 erased = false; 1684 1685 const auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get()); 1686 1687 if (!PieceI) 1688 continue; 1689 1690 const Stmt *start = PieceI->getStartLocation().getStmtOrNull(); 1691 const Stmt *end = PieceI->getEndLocation().getStmtOrNull(); 1692 1693 if (!start || !end) 1694 continue; 1695 1696 const Stmt *endParent = PM.getParent(end); 1697 if (!endParent) 1698 continue; 1699 1700 if (isConditionForTerminator(end, endParent)) 1701 continue; 1702 1703 SourceLocation FirstLoc = start->getBeginLoc(); 1704 SourceLocation SecondLoc = end->getBeginLoc(); 1705 1706 if (!SM.isWrittenInSameFile(FirstLoc, SecondLoc)) 1707 continue; 1708 if (SM.isBeforeInTranslationUnit(SecondLoc, FirstLoc)) 1709 std::swap(SecondLoc, FirstLoc); 1710 1711 SourceRange EdgeRange(FirstLoc, SecondLoc); 1712 Optional<size_t> ByteWidth = getLengthOnSingleLine(SM, EdgeRange); 1713 1714 // If the statements are on different lines, continue. 1715 if (!ByteWidth) 1716 continue; 1717 1718 const size_t MAX_PUNY_EDGE_LENGTH = 2; 1719 if (*ByteWidth <= MAX_PUNY_EDGE_LENGTH) { 1720 // FIXME: There are enough /bytes/ between the endpoints of the edge, but 1721 // there might not be enough /columns/. A proper user-visible column count 1722 // is probably too expensive, though. 1723 I = path.erase(I); 1724 erased = true; 1725 continue; 1726 } 1727 } 1728 } 1729 1730 static void removeIdenticalEvents(PathPieces &path) { 1731 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) { 1732 const auto *PieceI = dyn_cast<PathDiagnosticEventPiece>(I->get()); 1733 1734 if (!PieceI) 1735 continue; 1736 1737 PathPieces::iterator NextI = I; ++NextI; 1738 if (NextI == E) 1739 return; 1740 1741 const auto *PieceNextI = dyn_cast<PathDiagnosticEventPiece>(NextI->get()); 1742 1743 if (!PieceNextI) 1744 continue; 1745 1746 // Erase the second piece if it has the same exact message text. 1747 if (PieceI->getString() == PieceNextI->getString()) { 1748 path.erase(NextI); 1749 } 1750 } 1751 } 1752 1753 static bool optimizeEdges(const PathDiagnosticConstruct &C, PathPieces &path, 1754 OptimizedCallsSet &OCS) { 1755 bool hasChanges = false; 1756 const LocationContext *LC = C.getLocationContextFor(&path); 1757 assert(LC); 1758 const ParentMap &PM = LC->getParentMap(); 1759 const SourceManager &SM = C.getSourceManager(); 1760 1761 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) { 1762 // Optimize subpaths. 1763 if (auto *CallI = dyn_cast<PathDiagnosticCallPiece>(I->get())) { 1764 // Record the fact that a call has been optimized so we only do the 1765 // effort once. 1766 if (!OCS.count(CallI)) { 1767 while (optimizeEdges(C, CallI->path, OCS)) { 1768 } 1769 OCS.insert(CallI); 1770 } 1771 ++I; 1772 continue; 1773 } 1774 1775 // Pattern match the current piece and its successor. 1776 auto *PieceI = dyn_cast<PathDiagnosticControlFlowPiece>(I->get()); 1777 1778 if (!PieceI) { 1779 ++I; 1780 continue; 1781 } 1782 1783 const Stmt *s1Start = PieceI->getStartLocation().getStmtOrNull(); 1784 const Stmt *s1End = PieceI->getEndLocation().getStmtOrNull(); 1785 const Stmt *level1 = getStmtParent(s1Start, PM); 1786 const Stmt *level2 = getStmtParent(s1End, PM); 1787 1788 PathPieces::iterator NextI = I; ++NextI; 1789 if (NextI == E) 1790 break; 1791 1792 const auto *PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(NextI->get()); 1793 1794 if (!PieceNextI) { 1795 ++I; 1796 continue; 1797 } 1798 1799 const Stmt *s2Start = PieceNextI->getStartLocation().getStmtOrNull(); 1800 const Stmt *s2End = PieceNextI->getEndLocation().getStmtOrNull(); 1801 const Stmt *level3 = getStmtParent(s2Start, PM); 1802 const Stmt *level4 = getStmtParent(s2End, PM); 1803 1804 // Rule I. 1805 // 1806 // If we have two consecutive control edges whose end/begin locations 1807 // are at the same level (e.g. statements or top-level expressions within 1808 // a compound statement, or siblings share a single ancestor expression), 1809 // then merge them if they have no interesting intermediate event. 1810 // 1811 // For example: 1812 // 1813 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common 1814 // parent is '1'. Here 'x.y.z' represents the hierarchy of statements. 1815 // 1816 // NOTE: this will be limited later in cases where we add barriers 1817 // to prevent this optimization. 1818 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) { 1819 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1820 path.erase(NextI); 1821 hasChanges = true; 1822 continue; 1823 } 1824 1825 // Rule II. 1826 // 1827 // Eliminate edges between subexpressions and parent expressions 1828 // when the subexpression is consumed. 1829 // 1830 // NOTE: this will be limited later in cases where we add barriers 1831 // to prevent this optimization. 1832 if (s1End && s1End == s2Start && level2) { 1833 bool removeEdge = false; 1834 // Remove edges into the increment or initialization of a 1835 // loop that have no interleaving event. This means that 1836 // they aren't interesting. 1837 if (isIncrementOrInitInForLoop(s1End, level2)) 1838 removeEdge = true; 1839 // Next only consider edges that are not anchored on 1840 // the condition of a terminator. This are intermediate edges 1841 // that we might want to trim. 1842 else if (!isConditionForTerminator(level2, s1End)) { 1843 // Trim edges on expressions that are consumed by 1844 // the parent expression. 1845 if (isa<Expr>(s1End) && PM.isConsumedExpr(cast<Expr>(s1End))) { 1846 removeEdge = true; 1847 } 1848 // Trim edges where a lexical containment doesn't exist. 1849 // For example: 1850 // 1851 // X -> Y -> Z 1852 // 1853 // If 'Z' lexically contains Y (it is an ancestor) and 1854 // 'X' does not lexically contain Y (it is a descendant OR 1855 // it has no lexical relationship at all) then trim. 1856 // 1857 // This can eliminate edges where we dive into a subexpression 1858 // and then pop back out, etc. 1859 else if (s1Start && s2End && 1860 lexicalContains(PM, s2Start, s2End) && 1861 !lexicalContains(PM, s1End, s1Start)) { 1862 removeEdge = true; 1863 } 1864 // Trim edges from a subexpression back to the top level if the 1865 // subexpression is on a different line. 1866 // 1867 // A.1 -> A -> B 1868 // becomes 1869 // A.1 -> B 1870 // 1871 // These edges just look ugly and don't usually add anything. 1872 else if (s1Start && s2End && 1873 lexicalContains(PM, s1Start, s1End)) { 1874 SourceRange EdgeRange(PieceI->getEndLocation().asLocation(), 1875 PieceI->getStartLocation().asLocation()); 1876 if (!getLengthOnSingleLine(SM, EdgeRange).hasValue()) 1877 removeEdge = true; 1878 } 1879 } 1880 1881 if (removeEdge) { 1882 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1883 path.erase(NextI); 1884 hasChanges = true; 1885 continue; 1886 } 1887 } 1888 1889 // Optimize edges for ObjC fast-enumeration loops. 1890 // 1891 // (X -> collection) -> (collection -> element) 1892 // 1893 // becomes: 1894 // 1895 // (X -> element) 1896 if (s1End == s2Start) { 1897 const auto *FS = dyn_cast_or_null<ObjCForCollectionStmt>(level3); 1898 if (FS && FS->getCollection()->IgnoreParens() == s2Start && 1899 s2End == FS->getElement()) { 1900 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1901 path.erase(NextI); 1902 hasChanges = true; 1903 continue; 1904 } 1905 } 1906 1907 // No changes at this index? Move to the next one. 1908 ++I; 1909 } 1910 1911 if (!hasChanges) { 1912 // Adjust edges into subexpressions to make them more uniform 1913 // and aesthetically pleasing. 1914 addContextEdges(path, LC); 1915 // Remove "cyclical" edges that include one or more context edges. 1916 removeContextCycles(path, SM); 1917 // Hoist edges originating from branch conditions to branches 1918 // for simple branches. 1919 simplifySimpleBranches(path); 1920 // Remove any puny edges left over after primary optimization pass. 1921 removePunyEdges(path, SM, PM); 1922 // Remove identical events. 1923 removeIdenticalEvents(path); 1924 } 1925 1926 return hasChanges; 1927 } 1928 1929 /// Drop the very first edge in a path, which should be a function entry edge. 1930 /// 1931 /// If the first edge is not a function entry edge (say, because the first 1932 /// statement had an invalid source location), this function does nothing. 1933 // FIXME: We should just generate invalid edges anyway and have the optimizer 1934 // deal with them. 1935 static void dropFunctionEntryEdge(const PathDiagnosticConstruct &C, 1936 PathPieces &Path) { 1937 const auto *FirstEdge = 1938 dyn_cast<PathDiagnosticControlFlowPiece>(Path.front().get()); 1939 if (!FirstEdge) 1940 return; 1941 1942 const Decl *D = C.getLocationContextFor(&Path)->getDecl(); 1943 PathDiagnosticLocation EntryLoc = 1944 PathDiagnosticLocation::createBegin(D, C.getSourceManager()); 1945 if (FirstEdge->getStartLocation() != EntryLoc) 1946 return; 1947 1948 Path.pop_front(); 1949 } 1950 1951 /// Populate executes lines with lines containing at least one diagnostics. 1952 static void updateExecutedLinesWithDiagnosticPieces(PathDiagnostic &PD) { 1953 1954 PathPieces path = PD.path.flatten(/*ShouldFlattenMacros=*/true); 1955 FilesToLineNumsMap &ExecutedLines = PD.getExecutedLines(); 1956 1957 for (const auto &P : path) { 1958 FullSourceLoc Loc = P->getLocation().asLocation().getExpansionLoc(); 1959 FileID FID = Loc.getFileID(); 1960 unsigned LineNo = Loc.getLineNumber(); 1961 assert(FID.isValid()); 1962 ExecutedLines[FID].insert(LineNo); 1963 } 1964 } 1965 1966 PathDiagnosticConstruct::PathDiagnosticConstruct( 1967 const PathDiagnosticConsumer *PDC, const ExplodedNode *ErrorNode, 1968 const PathSensitiveBugReport *R) 1969 : Consumer(PDC), CurrentNode(ErrorNode), 1970 SM(CurrentNode->getCodeDecl().getASTContext().getSourceManager()), 1971 PD(generateEmptyDiagnosticForReport(R, getSourceManager())) { 1972 LCM[&PD->getActivePath()] = ErrorNode->getLocationContext(); 1973 } 1974 1975 PathDiagnosticBuilder::PathDiagnosticBuilder( 1976 BugReporterContext BRC, std::unique_ptr<ExplodedGraph> BugPath, 1977 PathSensitiveBugReport *r, const ExplodedNode *ErrorNode, 1978 std::unique_ptr<VisitorsDiagnosticsTy> VisitorsDiagnostics) 1979 : BugReporterContext(BRC), BugPath(std::move(BugPath)), R(r), 1980 ErrorNode(ErrorNode), 1981 VisitorsDiagnostics(std::move(VisitorsDiagnostics)) {} 1982 1983 std::unique_ptr<PathDiagnostic> 1984 PathDiagnosticBuilder::generate(const PathDiagnosticConsumer *PDC) const { 1985 PathDiagnosticConstruct Construct(PDC, ErrorNode, R); 1986 1987 const SourceManager &SM = getSourceManager(); 1988 const AnalyzerOptions &Opts = getAnalyzerOptions(); 1989 StringRef ErrorTag = ErrorNode->getLocation().getTag()->getTagDescription(); 1990 1991 // See whether we need to silence the checker/package. 1992 // FIXME: This will not work if the report was emitted with an incorrect tag. 1993 for (const std::string &CheckerOrPackage : Opts.SilencedCheckersAndPackages) { 1994 if (ErrorTag.startswith(CheckerOrPackage)) 1995 return nullptr; 1996 } 1997 1998 if (!PDC->shouldGenerateDiagnostics()) 1999 return generateEmptyDiagnosticForReport(R, getSourceManager()); 2000 2001 // Construct the final (warning) event for the bug report. 2002 auto EndNotes = VisitorsDiagnostics->find(ErrorNode); 2003 PathDiagnosticPieceRef LastPiece; 2004 if (EndNotes != VisitorsDiagnostics->end()) { 2005 assert(!EndNotes->second.empty()); 2006 LastPiece = EndNotes->second[0]; 2007 } else { 2008 LastPiece = BugReporterVisitor::getDefaultEndPath(*this, ErrorNode, 2009 *getBugReport()); 2010 } 2011 Construct.PD->setEndOfPath(LastPiece); 2012 2013 PathDiagnosticLocation PrevLoc = Construct.PD->getLocation(); 2014 // From the error node to the root, ascend the bug path and construct the bug 2015 // report. 2016 while (Construct.ascendToPrevNode()) { 2017 generatePathDiagnosticsForNode(Construct, PrevLoc); 2018 2019 auto VisitorNotes = VisitorsDiagnostics->find(Construct.getCurrentNode()); 2020 if (VisitorNotes == VisitorsDiagnostics->end()) 2021 continue; 2022 2023 // This is a workaround due to inability to put shared PathDiagnosticPiece 2024 // into a FoldingSet. 2025 std::set<llvm::FoldingSetNodeID> DeduplicationSet; 2026 2027 // Add pieces from custom visitors. 2028 for (const PathDiagnosticPieceRef &Note : VisitorNotes->second) { 2029 llvm::FoldingSetNodeID ID; 2030 Note->Profile(ID); 2031 if (!DeduplicationSet.insert(ID).second) 2032 continue; 2033 2034 if (PDC->shouldAddPathEdges()) 2035 addEdgeToPath(Construct.getActivePath(), PrevLoc, Note->getLocation()); 2036 updateStackPiecesWithMessage(Note, Construct.CallStack); 2037 Construct.getActivePath().push_front(Note); 2038 } 2039 } 2040 2041 if (PDC->shouldAddPathEdges()) { 2042 // Add an edge to the start of the function. 2043 // We'll prune it out later, but it helps make diagnostics more uniform. 2044 const StackFrameContext *CalleeLC = 2045 Construct.getLocationContextForActivePath()->getStackFrame(); 2046 const Decl *D = CalleeLC->getDecl(); 2047 addEdgeToPath(Construct.getActivePath(), PrevLoc, 2048 PathDiagnosticLocation::createBegin(D, SM)); 2049 } 2050 2051 2052 // Finally, prune the diagnostic path of uninteresting stuff. 2053 if (!Construct.PD->path.empty()) { 2054 if (R->shouldPrunePath() && Opts.ShouldPrunePaths) { 2055 bool stillHasNotes = 2056 removeUnneededCalls(Construct, Construct.getMutablePieces(), R); 2057 assert(stillHasNotes); 2058 (void)stillHasNotes; 2059 } 2060 2061 // Remove pop-up notes if needed. 2062 if (!Opts.ShouldAddPopUpNotes) 2063 removePopUpNotes(Construct.getMutablePieces()); 2064 2065 // Redirect all call pieces to have valid locations. 2066 adjustCallLocations(Construct.getMutablePieces()); 2067 removePiecesWithInvalidLocations(Construct.getMutablePieces()); 2068 2069 if (PDC->shouldAddPathEdges()) { 2070 2071 // Reduce the number of edges from a very conservative set 2072 // to an aesthetically pleasing subset that conveys the 2073 // necessary information. 2074 OptimizedCallsSet OCS; 2075 while (optimizeEdges(Construct, Construct.getMutablePieces(), OCS)) { 2076 } 2077 2078 // Drop the very first function-entry edge. It's not really necessary 2079 // for top-level functions. 2080 dropFunctionEntryEdge(Construct, Construct.getMutablePieces()); 2081 } 2082 2083 // Remove messages that are basically the same, and edges that may not 2084 // make sense. 2085 // We have to do this after edge optimization in the Extensive mode. 2086 removeRedundantMsgs(Construct.getMutablePieces()); 2087 removeEdgesToDefaultInitializers(Construct.getMutablePieces()); 2088 } 2089 2090 if (Opts.ShouldDisplayMacroExpansions) 2091 CompactMacroExpandedPieces(Construct.getMutablePieces(), SM); 2092 2093 return std::move(Construct.PD); 2094 } 2095 2096 //===----------------------------------------------------------------------===// 2097 // Methods for BugType and subclasses. 2098 //===----------------------------------------------------------------------===// 2099 2100 void BugType::anchor() {} 2101 2102 void BuiltinBug::anchor() {} 2103 2104 //===----------------------------------------------------------------------===// 2105 // Methods for BugReport and subclasses. 2106 //===----------------------------------------------------------------------===// 2107 2108 void PathSensitiveBugReport::addVisitor( 2109 std::unique_ptr<BugReporterVisitor> visitor) { 2110 if (!visitor) 2111 return; 2112 2113 llvm::FoldingSetNodeID ID; 2114 visitor->Profile(ID); 2115 2116 void *InsertPos = nullptr; 2117 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) { 2118 return; 2119 } 2120 2121 Callbacks.push_back(std::move(visitor)); 2122 } 2123 2124 void PathSensitiveBugReport::clearVisitors() { 2125 Callbacks.clear(); 2126 } 2127 2128 const Decl *PathSensitiveBugReport::getDeclWithIssue() const { 2129 const ExplodedNode *N = getErrorNode(); 2130 if (!N) 2131 return nullptr; 2132 2133 const LocationContext *LC = N->getLocationContext(); 2134 return LC->getStackFrame()->getDecl(); 2135 } 2136 2137 void BasicBugReport::Profile(llvm::FoldingSetNodeID& hash) const { 2138 hash.AddInteger(static_cast<int>(getKind())); 2139 hash.AddPointer(&BT); 2140 hash.AddString(Description); 2141 assert(Location.isValid()); 2142 Location.Profile(hash); 2143 2144 for (SourceRange range : Ranges) { 2145 if (!range.isValid()) 2146 continue; 2147 hash.AddInteger(range.getBegin().getRawEncoding()); 2148 hash.AddInteger(range.getEnd().getRawEncoding()); 2149 } 2150 } 2151 2152 void PathSensitiveBugReport::Profile(llvm::FoldingSetNodeID &hash) const { 2153 hash.AddInteger(static_cast<int>(getKind())); 2154 hash.AddPointer(&BT); 2155 hash.AddString(Description); 2156 PathDiagnosticLocation UL = getUniqueingLocation(); 2157 if (UL.isValid()) { 2158 UL.Profile(hash); 2159 } else { 2160 // TODO: The statement may be null if the report was emitted before any 2161 // statements were executed. In particular, some checkers by design 2162 // occasionally emit their reports in empty functions (that have no 2163 // statements in their body). Do we profile correctly in this case? 2164 hash.AddPointer(ErrorNode->getCurrentOrPreviousStmtForDiagnostics()); 2165 } 2166 2167 for (SourceRange range : Ranges) { 2168 if (!range.isValid()) 2169 continue; 2170 hash.AddInteger(range.getBegin().getRawEncoding()); 2171 hash.AddInteger(range.getEnd().getRawEncoding()); 2172 } 2173 } 2174 2175 template <class T> 2176 static void insertToInterestingnessMap( 2177 llvm::DenseMap<T, bugreporter::TrackingKind> &InterestingnessMap, T Val, 2178 bugreporter::TrackingKind TKind) { 2179 auto Result = InterestingnessMap.insert({Val, TKind}); 2180 2181 if (Result.second) 2182 return; 2183 2184 // Even if this symbol/region was already marked as interesting as a 2185 // condition, if we later mark it as interesting again but with 2186 // thorough tracking, overwrite it. Entities marked with thorough 2187 // interestiness are the most important (or most interesting, if you will), 2188 // and we wouldn't like to downplay their importance. 2189 2190 switch (TKind) { 2191 case bugreporter::TrackingKind::Thorough: 2192 Result.first->getSecond() = bugreporter::TrackingKind::Thorough; 2193 return; 2194 case bugreporter::TrackingKind::Condition: 2195 return; 2196 } 2197 2198 llvm_unreachable( 2199 "BugReport::markInteresting currently can only handle 2 different " 2200 "tracking kinds! Please define what tracking kind should this entitiy" 2201 "have, if it was already marked as interesting with a different kind!"); 2202 } 2203 2204 void PathSensitiveBugReport::markInteresting(SymbolRef sym, 2205 bugreporter::TrackingKind TKind) { 2206 if (!sym) 2207 return; 2208 2209 insertToInterestingnessMap(InterestingSymbols, sym, TKind); 2210 2211 if (const auto *meta = dyn_cast<SymbolMetadata>(sym)) 2212 markInteresting(meta->getRegion(), TKind); 2213 } 2214 2215 void PathSensitiveBugReport::markInteresting(const MemRegion *R, 2216 bugreporter::TrackingKind TKind) { 2217 if (!R) 2218 return; 2219 2220 R = R->getBaseRegion(); 2221 insertToInterestingnessMap(InterestingRegions, R, TKind); 2222 2223 if (const auto *SR = dyn_cast<SymbolicRegion>(R)) 2224 markInteresting(SR->getSymbol(), TKind); 2225 } 2226 2227 void PathSensitiveBugReport::markInteresting(SVal V, 2228 bugreporter::TrackingKind TKind) { 2229 markInteresting(V.getAsRegion(), TKind); 2230 markInteresting(V.getAsSymbol(), TKind); 2231 } 2232 2233 void PathSensitiveBugReport::markInteresting(const LocationContext *LC) { 2234 if (!LC) 2235 return; 2236 InterestingLocationContexts.insert(LC); 2237 } 2238 2239 Optional<bugreporter::TrackingKind> 2240 PathSensitiveBugReport::getInterestingnessKind(SVal V) const { 2241 auto RKind = getInterestingnessKind(V.getAsRegion()); 2242 auto SKind = getInterestingnessKind(V.getAsSymbol()); 2243 if (!RKind) 2244 return SKind; 2245 if (!SKind) 2246 return RKind; 2247 2248 // If either is marked with throrough tracking, return that, we wouldn't like 2249 // to downplay a note's importance by 'only' mentioning it as a condition. 2250 switch(*RKind) { 2251 case bugreporter::TrackingKind::Thorough: 2252 return RKind; 2253 case bugreporter::TrackingKind::Condition: 2254 return SKind; 2255 } 2256 2257 llvm_unreachable( 2258 "BugReport::getInterestingnessKind currently can only handle 2 different " 2259 "tracking kinds! Please define what tracking kind should we return here " 2260 "when the kind of getAsRegion() and getAsSymbol() is different!"); 2261 return None; 2262 } 2263 2264 Optional<bugreporter::TrackingKind> 2265 PathSensitiveBugReport::getInterestingnessKind(SymbolRef sym) const { 2266 if (!sym) 2267 return None; 2268 // We don't currently consider metadata symbols to be interesting 2269 // even if we know their region is interesting. Is that correct behavior? 2270 auto It = InterestingSymbols.find(sym); 2271 if (It == InterestingSymbols.end()) 2272 return None; 2273 return It->getSecond(); 2274 } 2275 2276 Optional<bugreporter::TrackingKind> 2277 PathSensitiveBugReport::getInterestingnessKind(const MemRegion *R) const { 2278 if (!R) 2279 return None; 2280 2281 R = R->getBaseRegion(); 2282 auto It = InterestingRegions.find(R); 2283 if (It != InterestingRegions.end()) 2284 return It->getSecond(); 2285 2286 if (const auto *SR = dyn_cast<SymbolicRegion>(R)) 2287 return getInterestingnessKind(SR->getSymbol()); 2288 return None; 2289 } 2290 2291 bool PathSensitiveBugReport::isInteresting(SVal V) const { 2292 return getInterestingnessKind(V).hasValue(); 2293 } 2294 2295 bool PathSensitiveBugReport::isInteresting(SymbolRef sym) const { 2296 return getInterestingnessKind(sym).hasValue(); 2297 } 2298 2299 bool PathSensitiveBugReport::isInteresting(const MemRegion *R) const { 2300 return getInterestingnessKind(R).hasValue(); 2301 } 2302 2303 bool PathSensitiveBugReport::isInteresting(const LocationContext *LC) const { 2304 if (!LC) 2305 return false; 2306 return InterestingLocationContexts.count(LC); 2307 } 2308 2309 const Stmt *PathSensitiveBugReport::getStmt() const { 2310 if (!ErrorNode) 2311 return nullptr; 2312 2313 ProgramPoint ProgP = ErrorNode->getLocation(); 2314 const Stmt *S = nullptr; 2315 2316 if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) { 2317 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit(); 2318 if (BE->getBlock() == &Exit) 2319 S = ErrorNode->getPreviousStmtForDiagnostics(); 2320 } 2321 if (!S) 2322 S = ErrorNode->getStmtForDiagnostics(); 2323 2324 return S; 2325 } 2326 2327 ArrayRef<SourceRange> 2328 PathSensitiveBugReport::getRanges() const { 2329 // If no custom ranges, add the range of the statement corresponding to 2330 // the error node. 2331 if (Ranges.empty() && isa_and_nonnull<Expr>(getStmt())) 2332 return ErrorNodeRange; 2333 2334 return Ranges; 2335 } 2336 2337 PathDiagnosticLocation 2338 PathSensitiveBugReport::getLocation() const { 2339 assert(ErrorNode && "Cannot create a location with a null node."); 2340 const Stmt *S = ErrorNode->getStmtForDiagnostics(); 2341 ProgramPoint P = ErrorNode->getLocation(); 2342 const LocationContext *LC = P.getLocationContext(); 2343 SourceManager &SM = 2344 ErrorNode->getState()->getStateManager().getContext().getSourceManager(); 2345 2346 if (!S) { 2347 // If this is an implicit call, return the implicit call point location. 2348 if (Optional<PreImplicitCall> PIE = P.getAs<PreImplicitCall>()) 2349 return PathDiagnosticLocation(PIE->getLocation(), SM); 2350 if (auto FE = P.getAs<FunctionExitPoint>()) { 2351 if (const ReturnStmt *RS = FE->getStmt()) 2352 return PathDiagnosticLocation::createBegin(RS, SM, LC); 2353 } 2354 S = ErrorNode->getNextStmtForDiagnostics(); 2355 } 2356 2357 if (S) { 2358 // For member expressions, return the location of the '.' or '->'. 2359 if (const auto *ME = dyn_cast<MemberExpr>(S)) 2360 return PathDiagnosticLocation::createMemberLoc(ME, SM); 2361 2362 // For binary operators, return the location of the operator. 2363 if (const auto *B = dyn_cast<BinaryOperator>(S)) 2364 return PathDiagnosticLocation::createOperatorLoc(B, SM); 2365 2366 if (P.getAs<PostStmtPurgeDeadSymbols>()) 2367 return PathDiagnosticLocation::createEnd(S, SM, LC); 2368 2369 if (S->getBeginLoc().isValid()) 2370 return PathDiagnosticLocation(S, SM, LC); 2371 2372 return PathDiagnosticLocation( 2373 PathDiagnosticLocation::getValidSourceLocation(S, LC), SM); 2374 } 2375 2376 return PathDiagnosticLocation::createDeclEnd(ErrorNode->getLocationContext(), 2377 SM); 2378 } 2379 2380 //===----------------------------------------------------------------------===// 2381 // Methods for BugReporter and subclasses. 2382 //===----------------------------------------------------------------------===// 2383 2384 const ExplodedGraph &PathSensitiveBugReporter::getGraph() const { 2385 return Eng.getGraph(); 2386 } 2387 2388 ProgramStateManager &PathSensitiveBugReporter::getStateManager() const { 2389 return Eng.getStateManager(); 2390 } 2391 2392 BugReporter::~BugReporter() { 2393 // Make sure reports are flushed. 2394 assert(StrBugTypes.empty() && 2395 "Destroying BugReporter before diagnostics are emitted!"); 2396 2397 // Free the bug reports we are tracking. 2398 for (const auto I : EQClassesVector) 2399 delete I; 2400 } 2401 2402 void BugReporter::FlushReports() { 2403 // We need to flush reports in deterministic order to ensure the order 2404 // of the reports is consistent between runs. 2405 for (const auto EQ : EQClassesVector) 2406 FlushReport(*EQ); 2407 2408 // BugReporter owns and deletes only BugTypes created implicitly through 2409 // EmitBasicReport. 2410 // FIXME: There are leaks from checkers that assume that the BugTypes they 2411 // create will be destroyed by the BugReporter. 2412 llvm::DeleteContainerSeconds(StrBugTypes); 2413 } 2414 2415 //===----------------------------------------------------------------------===// 2416 // PathDiagnostics generation. 2417 //===----------------------------------------------------------------------===// 2418 2419 namespace { 2420 2421 /// A wrapper around an ExplodedGraph that contains a single path from the root 2422 /// to the error node. 2423 class BugPathInfo { 2424 public: 2425 std::unique_ptr<ExplodedGraph> BugPath; 2426 PathSensitiveBugReport *Report; 2427 const ExplodedNode *ErrorNode; 2428 }; 2429 2430 /// A wrapper around an ExplodedGraph whose leafs are all error nodes. Can 2431 /// conveniently retrieve bug paths from a single error node to the root. 2432 class BugPathGetter { 2433 std::unique_ptr<ExplodedGraph> TrimmedGraph; 2434 2435 using PriorityMapTy = llvm::DenseMap<const ExplodedNode *, unsigned>; 2436 2437 /// Assign each node with its distance from the root. 2438 PriorityMapTy PriorityMap; 2439 2440 /// Since the getErrorNode() or BugReport refers to the original ExplodedGraph, 2441 /// we need to pair it to the error node of the constructed trimmed graph. 2442 using ReportNewNodePair = 2443 std::pair<PathSensitiveBugReport *, const ExplodedNode *>; 2444 SmallVector<ReportNewNodePair, 32> ReportNodes; 2445 2446 BugPathInfo CurrentBugPath; 2447 2448 /// A helper class for sorting ExplodedNodes by priority. 2449 template <bool Descending> 2450 class PriorityCompare { 2451 const PriorityMapTy &PriorityMap; 2452 2453 public: 2454 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {} 2455 2456 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const { 2457 PriorityMapTy::const_iterator LI = PriorityMap.find(LHS); 2458 PriorityMapTy::const_iterator RI = PriorityMap.find(RHS); 2459 PriorityMapTy::const_iterator E = PriorityMap.end(); 2460 2461 if (LI == E) 2462 return Descending; 2463 if (RI == E) 2464 return !Descending; 2465 2466 return Descending ? LI->second > RI->second 2467 : LI->second < RI->second; 2468 } 2469 2470 bool operator()(const ReportNewNodePair &LHS, 2471 const ReportNewNodePair &RHS) const { 2472 return (*this)(LHS.second, RHS.second); 2473 } 2474 }; 2475 2476 public: 2477 BugPathGetter(const ExplodedGraph *OriginalGraph, 2478 ArrayRef<PathSensitiveBugReport *> &bugReports); 2479 2480 BugPathInfo *getNextBugPath(); 2481 }; 2482 2483 } // namespace 2484 2485 BugPathGetter::BugPathGetter(const ExplodedGraph *OriginalGraph, 2486 ArrayRef<PathSensitiveBugReport *> &bugReports) { 2487 SmallVector<const ExplodedNode *, 32> Nodes; 2488 for (const auto I : bugReports) { 2489 assert(I->isValid() && 2490 "We only allow BugReporterVisitors and BugReporter itself to " 2491 "invalidate reports!"); 2492 Nodes.emplace_back(I->getErrorNode()); 2493 } 2494 2495 // The trimmed graph is created in the body of the constructor to ensure 2496 // that the DenseMaps have been initialized already. 2497 InterExplodedGraphMap ForwardMap; 2498 TrimmedGraph = OriginalGraph->trim(Nodes, &ForwardMap); 2499 2500 // Find the (first) error node in the trimmed graph. We just need to consult 2501 // the node map which maps from nodes in the original graph to nodes 2502 // in the new graph. 2503 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes; 2504 2505 for (PathSensitiveBugReport *Report : bugReports) { 2506 const ExplodedNode *NewNode = ForwardMap.lookup(Report->getErrorNode()); 2507 assert(NewNode && 2508 "Failed to construct a trimmed graph that contains this error " 2509 "node!"); 2510 ReportNodes.emplace_back(Report, NewNode); 2511 RemainingNodes.insert(NewNode); 2512 } 2513 2514 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph"); 2515 2516 // Perform a forward BFS to find all the shortest paths. 2517 std::queue<const ExplodedNode *> WS; 2518 2519 assert(TrimmedGraph->num_roots() == 1); 2520 WS.push(*TrimmedGraph->roots_begin()); 2521 unsigned Priority = 0; 2522 2523 while (!WS.empty()) { 2524 const ExplodedNode *Node = WS.front(); 2525 WS.pop(); 2526 2527 PriorityMapTy::iterator PriorityEntry; 2528 bool IsNew; 2529 std::tie(PriorityEntry, IsNew) = PriorityMap.insert({Node, Priority}); 2530 ++Priority; 2531 2532 if (!IsNew) { 2533 assert(PriorityEntry->second <= Priority); 2534 continue; 2535 } 2536 2537 if (RemainingNodes.erase(Node)) 2538 if (RemainingNodes.empty()) 2539 break; 2540 2541 for (const ExplodedNode *Succ : Node->succs()) 2542 WS.push(Succ); 2543 } 2544 2545 // Sort the error paths from longest to shortest. 2546 llvm::sort(ReportNodes, PriorityCompare<true>(PriorityMap)); 2547 } 2548 2549 BugPathInfo *BugPathGetter::getNextBugPath() { 2550 if (ReportNodes.empty()) 2551 return nullptr; 2552 2553 const ExplodedNode *OrigN; 2554 std::tie(CurrentBugPath.Report, OrigN) = ReportNodes.pop_back_val(); 2555 assert(PriorityMap.find(OrigN) != PriorityMap.end() && 2556 "error node not accessible from root"); 2557 2558 // Create a new graph with a single path. This is the graph that will be 2559 // returned to the caller. 2560 auto GNew = std::make_unique<ExplodedGraph>(); 2561 2562 // Now walk from the error node up the BFS path, always taking the 2563 // predeccessor with the lowest number. 2564 ExplodedNode *Succ = nullptr; 2565 while (true) { 2566 // Create the equivalent node in the new graph with the same state 2567 // and location. 2568 ExplodedNode *NewN = GNew->createUncachedNode( 2569 OrigN->getLocation(), OrigN->getState(), 2570 OrigN->getID(), OrigN->isSink()); 2571 2572 // Link up the new node with the previous node. 2573 if (Succ) 2574 Succ->addPredecessor(NewN, *GNew); 2575 else 2576 CurrentBugPath.ErrorNode = NewN; 2577 2578 Succ = NewN; 2579 2580 // Are we at the final node? 2581 if (OrigN->pred_empty()) { 2582 GNew->addRoot(NewN); 2583 break; 2584 } 2585 2586 // Find the next predeccessor node. We choose the node that is marked 2587 // with the lowest BFS number. 2588 OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(), 2589 PriorityCompare<false>(PriorityMap)); 2590 } 2591 2592 CurrentBugPath.BugPath = std::move(GNew); 2593 2594 return &CurrentBugPath; 2595 } 2596 2597 /// CompactMacroExpandedPieces - This function postprocesses a PathDiagnostic 2598 /// object and collapses PathDiagosticPieces that are expanded by macros. 2599 static void CompactMacroExpandedPieces(PathPieces &path, 2600 const SourceManager& SM) { 2601 using MacroStackTy = std::vector< 2602 std::pair<std::shared_ptr<PathDiagnosticMacroPiece>, SourceLocation>>; 2603 2604 using PiecesTy = std::vector<PathDiagnosticPieceRef>; 2605 2606 MacroStackTy MacroStack; 2607 PiecesTy Pieces; 2608 2609 for (PathPieces::const_iterator I = path.begin(), E = path.end(); 2610 I != E; ++I) { 2611 const auto &piece = *I; 2612 2613 // Recursively compact calls. 2614 if (auto *call = dyn_cast<PathDiagnosticCallPiece>(&*piece)) { 2615 CompactMacroExpandedPieces(call->path, SM); 2616 } 2617 2618 // Get the location of the PathDiagnosticPiece. 2619 const FullSourceLoc Loc = piece->getLocation().asLocation(); 2620 2621 // Determine the instantiation location, which is the location we group 2622 // related PathDiagnosticPieces. 2623 SourceLocation InstantiationLoc = Loc.isMacroID() ? 2624 SM.getExpansionLoc(Loc) : 2625 SourceLocation(); 2626 2627 if (Loc.isFileID()) { 2628 MacroStack.clear(); 2629 Pieces.push_back(piece); 2630 continue; 2631 } 2632 2633 assert(Loc.isMacroID()); 2634 2635 // Is the PathDiagnosticPiece within the same macro group? 2636 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) { 2637 MacroStack.back().first->subPieces.push_back(piece); 2638 continue; 2639 } 2640 2641 // We aren't in the same group. Are we descending into a new macro 2642 // or are part of an old one? 2643 std::shared_ptr<PathDiagnosticMacroPiece> MacroGroup; 2644 2645 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ? 2646 SM.getExpansionLoc(Loc) : 2647 SourceLocation(); 2648 2649 // Walk the entire macro stack. 2650 while (!MacroStack.empty()) { 2651 if (InstantiationLoc == MacroStack.back().second) { 2652 MacroGroup = MacroStack.back().first; 2653 break; 2654 } 2655 2656 if (ParentInstantiationLoc == MacroStack.back().second) { 2657 MacroGroup = MacroStack.back().first; 2658 break; 2659 } 2660 2661 MacroStack.pop_back(); 2662 } 2663 2664 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) { 2665 // Create a new macro group and add it to the stack. 2666 auto NewGroup = std::make_shared<PathDiagnosticMacroPiece>( 2667 PathDiagnosticLocation::createSingleLocation(piece->getLocation())); 2668 2669 if (MacroGroup) 2670 MacroGroup->subPieces.push_back(NewGroup); 2671 else { 2672 assert(InstantiationLoc.isFileID()); 2673 Pieces.push_back(NewGroup); 2674 } 2675 2676 MacroGroup = NewGroup; 2677 MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc)); 2678 } 2679 2680 // Finally, add the PathDiagnosticPiece to the group. 2681 MacroGroup->subPieces.push_back(piece); 2682 } 2683 2684 // Now take the pieces and construct a new PathDiagnostic. 2685 path.clear(); 2686 2687 path.insert(path.end(), Pieces.begin(), Pieces.end()); 2688 } 2689 2690 /// Generate notes from all visitors. 2691 /// Notes associated with {@code ErrorNode} are generated using 2692 /// {@code getEndPath}, and the rest are generated with {@code VisitNode}. 2693 static std::unique_ptr<VisitorsDiagnosticsTy> 2694 generateVisitorsDiagnostics(PathSensitiveBugReport *R, 2695 const ExplodedNode *ErrorNode, 2696 BugReporterContext &BRC) { 2697 std::unique_ptr<VisitorsDiagnosticsTy> Notes = 2698 std::make_unique<VisitorsDiagnosticsTy>(); 2699 PathSensitiveBugReport::VisitorList visitors; 2700 2701 // Run visitors on all nodes starting from the node *before* the last one. 2702 // The last node is reserved for notes generated with {@code getEndPath}. 2703 const ExplodedNode *NextNode = ErrorNode->getFirstPred(); 2704 while (NextNode) { 2705 2706 // At each iteration, move all visitors from report to visitor list. This is 2707 // important, because the Profile() functions of the visitors make sure that 2708 // a visitor isn't added multiple times for the same node, but it's fine 2709 // to add the a visitor with Profile() for different nodes (e.g. tracking 2710 // a region at different points of the symbolic execution). 2711 for (std::unique_ptr<BugReporterVisitor> &Visitor : R->visitors()) 2712 visitors.push_back(std::move(Visitor)); 2713 2714 R->clearVisitors(); 2715 2716 const ExplodedNode *Pred = NextNode->getFirstPred(); 2717 if (!Pred) { 2718 PathDiagnosticPieceRef LastPiece; 2719 for (auto &V : visitors) { 2720 V->finalizeVisitor(BRC, ErrorNode, *R); 2721 2722 if (auto Piece = V->getEndPath(BRC, ErrorNode, *R)) { 2723 assert(!LastPiece && 2724 "There can only be one final piece in a diagnostic."); 2725 assert(Piece->getKind() == PathDiagnosticPiece::Kind::Event && 2726 "The final piece must contain a message!"); 2727 LastPiece = std::move(Piece); 2728 (*Notes)[ErrorNode].push_back(LastPiece); 2729 } 2730 } 2731 break; 2732 } 2733 2734 for (auto &V : visitors) { 2735 auto P = V->VisitNode(NextNode, BRC, *R); 2736 if (P) 2737 (*Notes)[NextNode].push_back(std::move(P)); 2738 } 2739 2740 if (!R->isValid()) 2741 break; 2742 2743 NextNode = Pred; 2744 } 2745 2746 return Notes; 2747 } 2748 2749 Optional<PathDiagnosticBuilder> PathDiagnosticBuilder::findValidReport( 2750 ArrayRef<PathSensitiveBugReport *> &bugReports, 2751 PathSensitiveBugReporter &Reporter) { 2752 2753 BugPathGetter BugGraph(&Reporter.getGraph(), bugReports); 2754 2755 while (BugPathInfo *BugPath = BugGraph.getNextBugPath()) { 2756 // Find the BugReport with the original location. 2757 PathSensitiveBugReport *R = BugPath->Report; 2758 assert(R && "No original report found for sliced graph."); 2759 assert(R->isValid() && "Report selected by trimmed graph marked invalid."); 2760 const ExplodedNode *ErrorNode = BugPath->ErrorNode; 2761 2762 // Register refutation visitors first, if they mark the bug invalid no 2763 // further analysis is required 2764 R->addVisitor(std::make_unique<LikelyFalsePositiveSuppressionBRVisitor>()); 2765 2766 // Register additional node visitors. 2767 R->addVisitor(std::make_unique<NilReceiverBRVisitor>()); 2768 R->addVisitor(std::make_unique<ConditionBRVisitor>()); 2769 R->addVisitor(std::make_unique<TagVisitor>()); 2770 2771 BugReporterContext BRC(Reporter); 2772 2773 // Run all visitors on a given graph, once. 2774 std::unique_ptr<VisitorsDiagnosticsTy> visitorNotes = 2775 generateVisitorsDiagnostics(R, ErrorNode, BRC); 2776 2777 if (R->isValid()) { 2778 if (Reporter.getAnalyzerOptions().ShouldCrosscheckWithZ3) { 2779 // If crosscheck is enabled, remove all visitors, add the refutation 2780 // visitor and check again 2781 R->clearVisitors(); 2782 R->addVisitor(std::make_unique<FalsePositiveRefutationBRVisitor>()); 2783 2784 // We don't overrite the notes inserted by other visitors because the 2785 // refutation manager does not add any new note to the path 2786 generateVisitorsDiagnostics(R, BugPath->ErrorNode, BRC); 2787 } 2788 2789 // Check if the bug is still valid 2790 if (R->isValid()) 2791 return PathDiagnosticBuilder( 2792 std::move(BRC), std::move(BugPath->BugPath), BugPath->Report, 2793 BugPath->ErrorNode, std::move(visitorNotes)); 2794 } 2795 } 2796 2797 return {}; 2798 } 2799 2800 std::unique_ptr<DiagnosticForConsumerMapTy> 2801 PathSensitiveBugReporter::generatePathDiagnostics( 2802 ArrayRef<PathDiagnosticConsumer *> consumers, 2803 ArrayRef<PathSensitiveBugReport *> &bugReports) { 2804 assert(!bugReports.empty()); 2805 2806 auto Out = std::make_unique<DiagnosticForConsumerMapTy>(); 2807 2808 Optional<PathDiagnosticBuilder> PDB = 2809 PathDiagnosticBuilder::findValidReport(bugReports, *this); 2810 2811 if (PDB) { 2812 for (PathDiagnosticConsumer *PC : consumers) { 2813 if (std::unique_ptr<PathDiagnostic> PD = PDB->generate(PC)) { 2814 (*Out)[PC] = std::move(PD); 2815 } 2816 } 2817 } 2818 2819 return Out; 2820 } 2821 2822 void BugReporter::emitReport(std::unique_ptr<BugReport> R) { 2823 bool ValidSourceLoc = R->getLocation().isValid(); 2824 assert(ValidSourceLoc); 2825 // If we mess up in a release build, we'd still prefer to just drop the bug 2826 // instead of trying to go on. 2827 if (!ValidSourceLoc) 2828 return; 2829 2830 // Compute the bug report's hash to determine its equivalence class. 2831 llvm::FoldingSetNodeID ID; 2832 R->Profile(ID); 2833 2834 // Lookup the equivance class. If there isn't one, create it. 2835 void *InsertPos; 2836 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos); 2837 2838 if (!EQ) { 2839 EQ = new BugReportEquivClass(std::move(R)); 2840 EQClasses.InsertNode(EQ, InsertPos); 2841 EQClassesVector.push_back(EQ); 2842 } else 2843 EQ->AddReport(std::move(R)); 2844 } 2845 2846 void PathSensitiveBugReporter::emitReport(std::unique_ptr<BugReport> R) { 2847 if (auto PR = dyn_cast<PathSensitiveBugReport>(R.get())) 2848 if (const ExplodedNode *E = PR->getErrorNode()) { 2849 // An error node must either be a sink or have a tag, otherwise 2850 // it could get reclaimed before the path diagnostic is created. 2851 assert((E->isSink() || E->getLocation().getTag()) && 2852 "Error node must either be a sink or have a tag"); 2853 2854 const AnalysisDeclContext *DeclCtx = 2855 E->getLocationContext()->getAnalysisDeclContext(); 2856 // The source of autosynthesized body can be handcrafted AST or a model 2857 // file. The locations from handcrafted ASTs have no valid source 2858 // locations and have to be discarded. Locations from model files should 2859 // be preserved for processing and reporting. 2860 if (DeclCtx->isBodyAutosynthesized() && 2861 !DeclCtx->isBodyAutosynthesizedFromModelFile()) 2862 return; 2863 } 2864 2865 BugReporter::emitReport(std::move(R)); 2866 } 2867 2868 //===----------------------------------------------------------------------===// 2869 // Emitting reports in equivalence classes. 2870 //===----------------------------------------------------------------------===// 2871 2872 namespace { 2873 2874 struct FRIEC_WLItem { 2875 const ExplodedNode *N; 2876 ExplodedNode::const_succ_iterator I, E; 2877 2878 FRIEC_WLItem(const ExplodedNode *n) 2879 : N(n), I(N->succ_begin()), E(N->succ_end()) {} 2880 }; 2881 2882 } // namespace 2883 2884 BugReport *PathSensitiveBugReporter::findReportInEquivalenceClass( 2885 BugReportEquivClass &EQ, SmallVectorImpl<BugReport *> &bugReports) { 2886 // If we don't need to suppress any of the nodes because they are 2887 // post-dominated by a sink, simply add all the nodes in the equivalence class 2888 // to 'Nodes'. Any of the reports will serve as a "representative" report. 2889 assert(EQ.getReports().size() > 0); 2890 const BugType& BT = EQ.getReports()[0]->getBugType(); 2891 if (!BT.isSuppressOnSink()) { 2892 BugReport *R = EQ.getReports()[0].get(); 2893 for (auto &J : EQ.getReports()) { 2894 if (auto *PR = dyn_cast<PathSensitiveBugReport>(J.get())) { 2895 R = PR; 2896 bugReports.push_back(PR); 2897 } 2898 } 2899 return R; 2900 } 2901 2902 // For bug reports that should be suppressed when all paths are post-dominated 2903 // by a sink node, iterate through the reports in the equivalence class 2904 // until we find one that isn't post-dominated (if one exists). We use a 2905 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write 2906 // this as a recursive function, but we don't want to risk blowing out the 2907 // stack for very long paths. 2908 BugReport *exampleReport = nullptr; 2909 2910 for (const auto &I: EQ.getReports()) { 2911 auto *R = dyn_cast<PathSensitiveBugReport>(I.get()); 2912 if (!R) 2913 continue; 2914 2915 const ExplodedNode *errorNode = R->getErrorNode(); 2916 if (errorNode->isSink()) { 2917 llvm_unreachable( 2918 "BugType::isSuppressSink() should not be 'true' for sink end nodes"); 2919 } 2920 // No successors? By definition this nodes isn't post-dominated by a sink. 2921 if (errorNode->succ_empty()) { 2922 bugReports.push_back(R); 2923 if (!exampleReport) 2924 exampleReport = R; 2925 continue; 2926 } 2927 2928 // See if we are in a no-return CFG block. If so, treat this similarly 2929 // to being post-dominated by a sink. This works better when the analysis 2930 // is incomplete and we have never reached the no-return function call(s) 2931 // that we'd inevitably bump into on this path. 2932 if (const CFGBlock *ErrorB = errorNode->getCFGBlock()) 2933 if (ErrorB->isInevitablySinking()) 2934 continue; 2935 2936 // At this point we know that 'N' is not a sink and it has at least one 2937 // successor. Use a DFS worklist to find a non-sink end-of-path node. 2938 using WLItem = FRIEC_WLItem; 2939 using DFSWorkList = SmallVector<WLItem, 10>; 2940 2941 llvm::DenseMap<const ExplodedNode *, unsigned> Visited; 2942 2943 DFSWorkList WL; 2944 WL.push_back(errorNode); 2945 Visited[errorNode] = 1; 2946 2947 while (!WL.empty()) { 2948 WLItem &WI = WL.back(); 2949 assert(!WI.N->succ_empty()); 2950 2951 for (; WI.I != WI.E; ++WI.I) { 2952 const ExplodedNode *Succ = *WI.I; 2953 // End-of-path node? 2954 if (Succ->succ_empty()) { 2955 // If we found an end-of-path node that is not a sink. 2956 if (!Succ->isSink()) { 2957 bugReports.push_back(R); 2958 if (!exampleReport) 2959 exampleReport = R; 2960 WL.clear(); 2961 break; 2962 } 2963 // Found a sink? Continue on to the next successor. 2964 continue; 2965 } 2966 // Mark the successor as visited. If it hasn't been explored, 2967 // enqueue it to the DFS worklist. 2968 unsigned &mark = Visited[Succ]; 2969 if (!mark) { 2970 mark = 1; 2971 WL.push_back(Succ); 2972 break; 2973 } 2974 } 2975 2976 // The worklist may have been cleared at this point. First 2977 // check if it is empty before checking the last item. 2978 if (!WL.empty() && &WL.back() == &WI) 2979 WL.pop_back(); 2980 } 2981 } 2982 2983 // ExampleReport will be NULL if all the nodes in the equivalence class 2984 // were post-dominated by sinks. 2985 return exampleReport; 2986 } 2987 2988 void BugReporter::FlushReport(BugReportEquivClass& EQ) { 2989 SmallVector<BugReport*, 10> bugReports; 2990 BugReport *report = findReportInEquivalenceClass(EQ, bugReports); 2991 if (!report) 2992 return; 2993 2994 ArrayRef<PathDiagnosticConsumer*> Consumers = getPathDiagnosticConsumers(); 2995 std::unique_ptr<DiagnosticForConsumerMapTy> Diagnostics = 2996 generateDiagnosticForConsumerMap(report, Consumers, bugReports); 2997 2998 for (auto &P : *Diagnostics) { 2999 PathDiagnosticConsumer *Consumer = P.first; 3000 std::unique_ptr<PathDiagnostic> &PD = P.second; 3001 3002 // If the path is empty, generate a single step path with the location 3003 // of the issue. 3004 if (PD->path.empty()) { 3005 PathDiagnosticLocation L = report->getLocation(); 3006 auto piece = std::make_unique<PathDiagnosticEventPiece>( 3007 L, report->getDescription()); 3008 for (SourceRange Range : report->getRanges()) 3009 piece->addRange(Range); 3010 PD->setEndOfPath(std::move(piece)); 3011 } 3012 3013 PathPieces &Pieces = PD->getMutablePieces(); 3014 if (getAnalyzerOptions().ShouldDisplayNotesAsEvents) { 3015 // For path diagnostic consumers that don't support extra notes, 3016 // we may optionally convert those to path notes. 3017 for (auto I = report->getNotes().rbegin(), 3018 E = report->getNotes().rend(); I != E; ++I) { 3019 PathDiagnosticNotePiece *Piece = I->get(); 3020 auto ConvertedPiece = std::make_shared<PathDiagnosticEventPiece>( 3021 Piece->getLocation(), Piece->getString()); 3022 for (const auto &R: Piece->getRanges()) 3023 ConvertedPiece->addRange(R); 3024 3025 Pieces.push_front(std::move(ConvertedPiece)); 3026 } 3027 } else { 3028 for (auto I = report->getNotes().rbegin(), 3029 E = report->getNotes().rend(); I != E; ++I) 3030 Pieces.push_front(*I); 3031 } 3032 3033 for (const auto &I : report->getFixits()) 3034 Pieces.back()->addFixit(I); 3035 3036 updateExecutedLinesWithDiagnosticPieces(*PD); 3037 Consumer->HandlePathDiagnostic(std::move(PD)); 3038 } 3039 } 3040 3041 /// Insert all lines participating in the function signature \p Signature 3042 /// into \p ExecutedLines. 3043 static void populateExecutedLinesWithFunctionSignature( 3044 const Decl *Signature, const SourceManager &SM, 3045 FilesToLineNumsMap &ExecutedLines) { 3046 SourceRange SignatureSourceRange; 3047 const Stmt* Body = Signature->getBody(); 3048 if (const auto FD = dyn_cast<FunctionDecl>(Signature)) { 3049 SignatureSourceRange = FD->getSourceRange(); 3050 } else if (const auto OD = dyn_cast<ObjCMethodDecl>(Signature)) { 3051 SignatureSourceRange = OD->getSourceRange(); 3052 } else { 3053 return; 3054 } 3055 SourceLocation Start = SignatureSourceRange.getBegin(); 3056 SourceLocation End = Body ? Body->getSourceRange().getBegin() 3057 : SignatureSourceRange.getEnd(); 3058 if (!Start.isValid() || !End.isValid()) 3059 return; 3060 unsigned StartLine = SM.getExpansionLineNumber(Start); 3061 unsigned EndLine = SM.getExpansionLineNumber(End); 3062 3063 FileID FID = SM.getFileID(SM.getExpansionLoc(Start)); 3064 for (unsigned Line = StartLine; Line <= EndLine; Line++) 3065 ExecutedLines[FID].insert(Line); 3066 } 3067 3068 static void populateExecutedLinesWithStmt( 3069 const Stmt *S, const SourceManager &SM, 3070 FilesToLineNumsMap &ExecutedLines) { 3071 SourceLocation Loc = S->getSourceRange().getBegin(); 3072 if (!Loc.isValid()) 3073 return; 3074 SourceLocation ExpansionLoc = SM.getExpansionLoc(Loc); 3075 FileID FID = SM.getFileID(ExpansionLoc); 3076 unsigned LineNo = SM.getExpansionLineNumber(ExpansionLoc); 3077 ExecutedLines[FID].insert(LineNo); 3078 } 3079 3080 /// \return all executed lines including function signatures on the path 3081 /// starting from \p N. 3082 static std::unique_ptr<FilesToLineNumsMap> 3083 findExecutedLines(const SourceManager &SM, const ExplodedNode *N) { 3084 auto ExecutedLines = std::make_unique<FilesToLineNumsMap>(); 3085 3086 while (N) { 3087 if (N->getFirstPred() == nullptr) { 3088 // First node: show signature of the entrance point. 3089 const Decl *D = N->getLocationContext()->getDecl(); 3090 populateExecutedLinesWithFunctionSignature(D, SM, *ExecutedLines); 3091 } else if (auto CE = N->getLocationAs<CallEnter>()) { 3092 // Inlined function: show signature. 3093 const Decl* D = CE->getCalleeContext()->getDecl(); 3094 populateExecutedLinesWithFunctionSignature(D, SM, *ExecutedLines); 3095 } else if (const Stmt *S = N->getStmtForDiagnostics()) { 3096 populateExecutedLinesWithStmt(S, SM, *ExecutedLines); 3097 3098 // Show extra context for some parent kinds. 3099 const Stmt *P = N->getParentMap().getParent(S); 3100 3101 // The path exploration can die before the node with the associated 3102 // return statement is generated, but we do want to show the whole 3103 // return. 3104 if (const auto *RS = dyn_cast_or_null<ReturnStmt>(P)) { 3105 populateExecutedLinesWithStmt(RS, SM, *ExecutedLines); 3106 P = N->getParentMap().getParent(RS); 3107 } 3108 3109 if (P && (isa<SwitchCase>(P) || isa<LabelStmt>(P))) 3110 populateExecutedLinesWithStmt(P, SM, *ExecutedLines); 3111 } 3112 3113 N = N->getFirstPred(); 3114 } 3115 return ExecutedLines; 3116 } 3117 3118 std::unique_ptr<DiagnosticForConsumerMapTy> 3119 BugReporter::generateDiagnosticForConsumerMap( 3120 BugReport *exampleReport, ArrayRef<PathDiagnosticConsumer *> consumers, 3121 ArrayRef<BugReport *> bugReports) { 3122 auto *basicReport = cast<BasicBugReport>(exampleReport); 3123 auto Out = std::make_unique<DiagnosticForConsumerMapTy>(); 3124 for (auto *Consumer : consumers) 3125 (*Out)[Consumer] = generateDiagnosticForBasicReport(basicReport); 3126 return Out; 3127 } 3128 3129 static PathDiagnosticCallPiece * 3130 getFirstStackedCallToHeaderFile(PathDiagnosticCallPiece *CP, 3131 const SourceManager &SMgr) { 3132 SourceLocation CallLoc = CP->callEnter.asLocation(); 3133 3134 // If the call is within a macro, don't do anything (for now). 3135 if (CallLoc.isMacroID()) 3136 return nullptr; 3137 3138 assert(AnalysisManager::isInCodeFile(CallLoc, SMgr) && 3139 "The call piece should not be in a header file."); 3140 3141 // Check if CP represents a path through a function outside of the main file. 3142 if (!AnalysisManager::isInCodeFile(CP->callEnterWithin.asLocation(), SMgr)) 3143 return CP; 3144 3145 const PathPieces &Path = CP->path; 3146 if (Path.empty()) 3147 return nullptr; 3148 3149 // Check if the last piece in the callee path is a call to a function outside 3150 // of the main file. 3151 if (auto *CPInner = dyn_cast<PathDiagnosticCallPiece>(Path.back().get())) 3152 return getFirstStackedCallToHeaderFile(CPInner, SMgr); 3153 3154 // Otherwise, the last piece is in the main file. 3155 return nullptr; 3156 } 3157 3158 static void resetDiagnosticLocationToMainFile(PathDiagnostic &PD) { 3159 if (PD.path.empty()) 3160 return; 3161 3162 PathDiagnosticPiece *LastP = PD.path.back().get(); 3163 assert(LastP); 3164 const SourceManager &SMgr = LastP->getLocation().getManager(); 3165 3166 // We only need to check if the report ends inside headers, if the last piece 3167 // is a call piece. 3168 if (auto *CP = dyn_cast<PathDiagnosticCallPiece>(LastP)) { 3169 CP = getFirstStackedCallToHeaderFile(CP, SMgr); 3170 if (CP) { 3171 // Mark the piece. 3172 CP->setAsLastInMainSourceFile(); 3173 3174 // Update the path diagnostic message. 3175 const auto *ND = dyn_cast<NamedDecl>(CP->getCallee()); 3176 if (ND) { 3177 SmallString<200> buf; 3178 llvm::raw_svector_ostream os(buf); 3179 os << " (within a call to '" << ND->getDeclName() << "')"; 3180 PD.appendToDesc(os.str()); 3181 } 3182 3183 // Reset the report containing declaration and location. 3184 PD.setDeclWithIssue(CP->getCaller()); 3185 PD.setLocation(CP->getLocation()); 3186 3187 return; 3188 } 3189 } 3190 } 3191 3192 3193 3194 std::unique_ptr<DiagnosticForConsumerMapTy> 3195 PathSensitiveBugReporter::generateDiagnosticForConsumerMap( 3196 BugReport *exampleReport, ArrayRef<PathDiagnosticConsumer *> consumers, 3197 ArrayRef<BugReport *> bugReports) { 3198 std::vector<BasicBugReport *> BasicBugReports; 3199 std::vector<PathSensitiveBugReport *> PathSensitiveBugReports; 3200 if (isa<BasicBugReport>(exampleReport)) 3201 return BugReporter::generateDiagnosticForConsumerMap(exampleReport, 3202 consumers, bugReports); 3203 3204 // Generate the full path sensitive diagnostic, using the generation scheme 3205 // specified by the PathDiagnosticConsumer. Note that we have to generate 3206 // path diagnostics even for consumers which do not support paths, because 3207 // the BugReporterVisitors may mark this bug as a false positive. 3208 assert(!bugReports.empty()); 3209 MaxBugClassSize.updateMax(bugReports.size()); 3210 3211 // Avoid copying the whole array because there may be a lot of reports. 3212 ArrayRef<PathSensitiveBugReport *> convertedArrayOfReports( 3213 reinterpret_cast<PathSensitiveBugReport *const *>(&*bugReports.begin()), 3214 reinterpret_cast<PathSensitiveBugReport *const *>(&*bugReports.end())); 3215 std::unique_ptr<DiagnosticForConsumerMapTy> Out = generatePathDiagnostics( 3216 consumers, convertedArrayOfReports); 3217 3218 if (Out->empty()) 3219 return Out; 3220 3221 MaxValidBugClassSize.updateMax(bugReports.size()); 3222 3223 // Examine the report and see if the last piece is in a header. Reset the 3224 // report location to the last piece in the main source file. 3225 const AnalyzerOptions &Opts = getAnalyzerOptions(); 3226 for (auto const &P : *Out) 3227 if (Opts.ShouldReportIssuesInMainSourceFile && !Opts.AnalyzeAll) 3228 resetDiagnosticLocationToMainFile(*P.second); 3229 3230 return Out; 3231 } 3232 3233 void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, 3234 const CheckerBase *Checker, StringRef Name, 3235 StringRef Category, StringRef Str, 3236 PathDiagnosticLocation Loc, 3237 ArrayRef<SourceRange> Ranges, 3238 ArrayRef<FixItHint> Fixits) { 3239 EmitBasicReport(DeclWithIssue, Checker->getCheckerName(), Name, Category, Str, 3240 Loc, Ranges, Fixits); 3241 } 3242 3243 void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, 3244 CheckerNameRef CheckName, 3245 StringRef name, StringRef category, 3246 StringRef str, PathDiagnosticLocation Loc, 3247 ArrayRef<SourceRange> Ranges, 3248 ArrayRef<FixItHint> Fixits) { 3249 // 'BT' is owned by BugReporter. 3250 BugType *BT = getBugTypeForName(CheckName, name, category); 3251 auto R = std::make_unique<BasicBugReport>(*BT, str, Loc); 3252 R->setDeclWithIssue(DeclWithIssue); 3253 for (const auto &SR : Ranges) 3254 R->addRange(SR); 3255 for (const auto &FH : Fixits) 3256 R->addFixItHint(FH); 3257 emitReport(std::move(R)); 3258 } 3259 3260 BugType *BugReporter::getBugTypeForName(CheckerNameRef CheckName, 3261 StringRef name, StringRef category) { 3262 SmallString<136> fullDesc; 3263 llvm::raw_svector_ostream(fullDesc) << CheckName.getName() << ":" << name 3264 << ":" << category; 3265 BugType *&BT = StrBugTypes[fullDesc]; 3266 if (!BT) 3267 BT = new BugType(CheckName, name, category); 3268 return BT; 3269 } 3270