BugReporter.cpp revision f94cb007d03031bcf3d1b02f6a683a189e934953
1// BugReporter.cpp - Generate PathDiagnostics for Bugs ------------*- C++ -*--// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines BugReporter, a utility class for generating 11// PathDiagnostics. 12// 13//===----------------------------------------------------------------------===// 14 15#define DEBUG_TYPE "BugReporter" 16 17#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 18#include "clang/AST/ASTContext.h" 19#include "clang/AST/DeclObjC.h" 20#include "clang/AST/Expr.h" 21#include "clang/AST/ParentMap.h" 22#include "clang/AST/StmtObjC.h" 23#include "clang/Analysis/CFG.h" 24#include "clang/Analysis/ProgramPoint.h" 25#include "clang/Basic/SourceManager.h" 26#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 27#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h" 28#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 29#include "llvm/ADT/DenseMap.h" 30#include "llvm/ADT/IntrusiveRefCntPtr.h" 31#include "llvm/ADT/OwningPtr.h" 32#include "llvm/ADT/STLExtras.h" 33#include "llvm/ADT/SmallString.h" 34#include "llvm/ADT/Statistic.h" 35#include "llvm/Support/raw_ostream.h" 36#include <queue> 37 38using namespace clang; 39using namespace ento; 40 41STATISTIC(MaxBugClassSize, 42 "The maximum number of bug reports in the same equivalence class"); 43STATISTIC(MaxValidBugClassSize, 44 "The maximum number of bug reports in the same equivalence class " 45 "where at least one report is valid (not suppressed)"); 46 47BugReporterVisitor::~BugReporterVisitor() {} 48 49void BugReporterContext::anchor() {} 50 51//===----------------------------------------------------------------------===// 52// Helper routines for walking the ExplodedGraph and fetching statements. 53//===----------------------------------------------------------------------===// 54 55static const Stmt *GetPreviousStmt(const ExplodedNode *N) { 56 for (N = N->getFirstPred(); N; N = N->getFirstPred()) 57 if (const Stmt *S = PathDiagnosticLocation::getStmt(N)) 58 return S; 59 60 return 0; 61} 62 63static inline const Stmt* 64GetCurrentOrPreviousStmt(const ExplodedNode *N) { 65 if (const Stmt *S = PathDiagnosticLocation::getStmt(N)) 66 return S; 67 68 return GetPreviousStmt(N); 69} 70 71//===----------------------------------------------------------------------===// 72// Diagnostic cleanup. 73//===----------------------------------------------------------------------===// 74 75static PathDiagnosticEventPiece * 76eventsDescribeSameCondition(PathDiagnosticEventPiece *X, 77 PathDiagnosticEventPiece *Y) { 78 // Prefer diagnostics that come from ConditionBRVisitor over 79 // those that came from TrackConstraintBRVisitor. 80 const void *tagPreferred = ConditionBRVisitor::getTag(); 81 const void *tagLesser = TrackConstraintBRVisitor::getTag(); 82 83 if (X->getLocation() != Y->getLocation()) 84 return 0; 85 86 if (X->getTag() == tagPreferred && Y->getTag() == tagLesser) 87 return X; 88 89 if (Y->getTag() == tagPreferred && X->getTag() == tagLesser) 90 return Y; 91 92 return 0; 93} 94 95/// An optimization pass over PathPieces that removes redundant diagnostics 96/// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both 97/// BugReporterVisitors use different methods to generate diagnostics, with 98/// one capable of emitting diagnostics in some cases but not in others. This 99/// can lead to redundant diagnostic pieces at the same point in a path. 100static void removeRedundantMsgs(PathPieces &path) { 101 unsigned N = path.size(); 102 if (N < 2) 103 return; 104 // NOTE: this loop intentionally is not using an iterator. Instead, we 105 // are streaming the path and modifying it in place. This is done by 106 // grabbing the front, processing it, and if we decide to keep it append 107 // it to the end of the path. The entire path is processed in this way. 108 for (unsigned i = 0; i < N; ++i) { 109 IntrusiveRefCntPtr<PathDiagnosticPiece> piece(path.front()); 110 path.pop_front(); 111 112 switch (piece->getKind()) { 113 case clang::ento::PathDiagnosticPiece::Call: 114 removeRedundantMsgs(cast<PathDiagnosticCallPiece>(piece)->path); 115 break; 116 case clang::ento::PathDiagnosticPiece::Macro: 117 removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(piece)->subPieces); 118 break; 119 case clang::ento::PathDiagnosticPiece::ControlFlow: 120 break; 121 case clang::ento::PathDiagnosticPiece::Event: { 122 if (i == N-1) 123 break; 124 125 if (PathDiagnosticEventPiece *nextEvent = 126 dyn_cast<PathDiagnosticEventPiece>(path.front().getPtr())) { 127 PathDiagnosticEventPiece *event = 128 cast<PathDiagnosticEventPiece>(piece); 129 // Check to see if we should keep one of the two pieces. If we 130 // come up with a preference, record which piece to keep, and consume 131 // another piece from the path. 132 if (PathDiagnosticEventPiece *pieceToKeep = 133 eventsDescribeSameCondition(event, nextEvent)) { 134 piece = pieceToKeep; 135 path.pop_front(); 136 ++i; 137 } 138 } 139 break; 140 } 141 } 142 path.push_back(piece); 143 } 144} 145 146/// A map from PathDiagnosticPiece to the LocationContext of the inlined 147/// function call it represents. 148typedef llvm::DenseMap<const PathPieces *, const LocationContext *> 149 LocationContextMap; 150 151/// Recursively scan through a path and prune out calls and macros pieces 152/// that aren't needed. Return true if afterwards the path contains 153/// "interesting stuff" which means it shouldn't be pruned from the parent path. 154static bool removeUnneededCalls(PathPieces &pieces, BugReport *R, 155 LocationContextMap &LCM) { 156 bool containsSomethingInteresting = false; 157 const unsigned N = pieces.size(); 158 159 for (unsigned i = 0 ; i < N ; ++i) { 160 // Remove the front piece from the path. If it is still something we 161 // want to keep once we are done, we will push it back on the end. 162 IntrusiveRefCntPtr<PathDiagnosticPiece> piece(pieces.front()); 163 pieces.pop_front(); 164 165 // Throw away pieces with invalid locations. Note that we can't throw away 166 // calls just yet because they might have something interesting inside them. 167 // If so, their locations will be adjusted as necessary later. 168 if (piece->getKind() != PathDiagnosticPiece::Call && 169 piece->getLocation().asLocation().isInvalid()) 170 continue; 171 172 switch (piece->getKind()) { 173 case PathDiagnosticPiece::Call: { 174 PathDiagnosticCallPiece *call = cast<PathDiagnosticCallPiece>(piece); 175 // Check if the location context is interesting. 176 assert(LCM.count(&call->path)); 177 if (R->isInteresting(LCM[&call->path])) { 178 containsSomethingInteresting = true; 179 break; 180 } 181 182 if (!removeUnneededCalls(call->path, R, LCM)) 183 continue; 184 185 containsSomethingInteresting = true; 186 break; 187 } 188 case PathDiagnosticPiece::Macro: { 189 PathDiagnosticMacroPiece *macro = cast<PathDiagnosticMacroPiece>(piece); 190 if (!removeUnneededCalls(macro->subPieces, R, LCM)) 191 continue; 192 containsSomethingInteresting = true; 193 break; 194 } 195 case PathDiagnosticPiece::Event: { 196 PathDiagnosticEventPiece *event = cast<PathDiagnosticEventPiece>(piece); 197 198 // We never throw away an event, but we do throw it away wholesale 199 // as part of a path if we throw the entire path away. 200 containsSomethingInteresting |= !event->isPrunable(); 201 break; 202 } 203 case PathDiagnosticPiece::ControlFlow: 204 break; 205 } 206 207 pieces.push_back(piece); 208 } 209 210 return containsSomethingInteresting; 211} 212 213/// Returns true if the given decl has been implicitly given a body, either by 214/// the analyzer or by the compiler proper. 215static bool hasImplicitBody(const Decl *D) { 216 assert(D); 217 return D->isImplicit() || !D->hasBody(); 218} 219 220/// Recursively scan through a path and make sure that all call pieces have 221/// valid locations. Note that all other pieces with invalid locations should 222/// have already been pruned out. 223static void adjustCallLocations(PathPieces &Pieces, 224 PathDiagnosticLocation *LastCallLocation = 0) { 225 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E; ++I) { 226 PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I); 227 228 if (!Call) { 229 assert((*I)->getLocation().asLocation().isValid()); 230 continue; 231 } 232 233 if (LastCallLocation) { 234 bool CallerIsImplicit = hasImplicitBody(Call->getCaller()); 235 if (CallerIsImplicit || !Call->callEnter.asLocation().isValid()) 236 Call->callEnter = *LastCallLocation; 237 if (CallerIsImplicit || !Call->callReturn.asLocation().isValid()) 238 Call->callReturn = *LastCallLocation; 239 } 240 241 // Recursively clean out the subclass. Keep this call around if 242 // it contains any informative diagnostics. 243 PathDiagnosticLocation *ThisCallLocation; 244 if (Call->callEnterWithin.asLocation().isValid() && 245 !hasImplicitBody(Call->getCallee())) 246 ThisCallLocation = &Call->callEnterWithin; 247 else 248 ThisCallLocation = &Call->callEnter; 249 250 assert(ThisCallLocation && "Outermost call has an invalid location"); 251 adjustCallLocations(Call->path, ThisCallLocation); 252 } 253} 254 255//===----------------------------------------------------------------------===// 256// PathDiagnosticBuilder and its associated routines and helper objects. 257//===----------------------------------------------------------------------===// 258 259namespace { 260class NodeMapClosure : public BugReport::NodeResolver { 261 InterExplodedGraphMap &M; 262public: 263 NodeMapClosure(InterExplodedGraphMap &m) : M(m) {} 264 265 const ExplodedNode *getOriginalNode(const ExplodedNode *N) { 266 return M.lookup(N); 267 } 268}; 269 270class PathDiagnosticBuilder : public BugReporterContext { 271 BugReport *R; 272 PathDiagnosticConsumer *PDC; 273 NodeMapClosure NMC; 274public: 275 const LocationContext *LC; 276 277 PathDiagnosticBuilder(GRBugReporter &br, 278 BugReport *r, InterExplodedGraphMap &Backmap, 279 PathDiagnosticConsumer *pdc) 280 : BugReporterContext(br), 281 R(r), PDC(pdc), NMC(Backmap), LC(r->getErrorNode()->getLocationContext()) 282 {} 283 284 PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N); 285 286 PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os, 287 const ExplodedNode *N); 288 289 BugReport *getBugReport() { return R; } 290 291 Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); } 292 293 ParentMap& getParentMap() { return LC->getParentMap(); } 294 295 const Stmt *getParent(const Stmt *S) { 296 return getParentMap().getParent(S); 297 } 298 299 virtual NodeMapClosure& getNodeResolver() { return NMC; } 300 301 PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S); 302 303 PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const { 304 return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Extensive; 305 } 306 307 bool supportsLogicalOpControlFlow() const { 308 return PDC ? PDC->supportsLogicalOpControlFlow() : true; 309 } 310}; 311} // end anonymous namespace 312 313PathDiagnosticLocation 314PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) { 315 if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N)) 316 return PathDiagnosticLocation(S, getSourceManager(), LC); 317 318 return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(), 319 getSourceManager()); 320} 321 322PathDiagnosticLocation 323PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os, 324 const ExplodedNode *N) { 325 326 // Slow, but probably doesn't matter. 327 if (os.str().empty()) 328 os << ' '; 329 330 const PathDiagnosticLocation &Loc = ExecutionContinues(N); 331 332 if (Loc.asStmt()) 333 os << "Execution continues on line " 334 << getSourceManager().getExpansionLineNumber(Loc.asLocation()) 335 << '.'; 336 else { 337 os << "Execution jumps to the end of the "; 338 const Decl *D = N->getLocationContext()->getDecl(); 339 if (isa<ObjCMethodDecl>(D)) 340 os << "method"; 341 else if (isa<FunctionDecl>(D)) 342 os << "function"; 343 else { 344 assert(isa<BlockDecl>(D)); 345 os << "anonymous block"; 346 } 347 os << '.'; 348 } 349 350 return Loc; 351} 352 353static bool IsNested(const Stmt *S, ParentMap &PM) { 354 if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S))) 355 return true; 356 357 const Stmt *Parent = PM.getParentIgnoreParens(S); 358 359 if (Parent) 360 switch (Parent->getStmtClass()) { 361 case Stmt::ForStmtClass: 362 case Stmt::DoStmtClass: 363 case Stmt::WhileStmtClass: 364 return true; 365 default: 366 break; 367 } 368 369 return false; 370} 371 372PathDiagnosticLocation 373PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) { 374 assert(S && "Null Stmt *passed to getEnclosingStmtLocation"); 375 ParentMap &P = getParentMap(); 376 SourceManager &SMgr = getSourceManager(); 377 378 while (IsNested(S, P)) { 379 const Stmt *Parent = P.getParentIgnoreParens(S); 380 381 if (!Parent) 382 break; 383 384 switch (Parent->getStmtClass()) { 385 case Stmt::BinaryOperatorClass: { 386 const BinaryOperator *B = cast<BinaryOperator>(Parent); 387 if (B->isLogicalOp()) 388 return PathDiagnosticLocation(S, SMgr, LC); 389 break; 390 } 391 case Stmt::CompoundStmtClass: 392 case Stmt::StmtExprClass: 393 return PathDiagnosticLocation(S, SMgr, LC); 394 case Stmt::ChooseExprClass: 395 // Similar to '?' if we are referring to condition, just have the edge 396 // point to the entire choose expression. 397 if (cast<ChooseExpr>(Parent)->getCond() == S) 398 return PathDiagnosticLocation(Parent, SMgr, LC); 399 else 400 return PathDiagnosticLocation(S, SMgr, LC); 401 case Stmt::BinaryConditionalOperatorClass: 402 case Stmt::ConditionalOperatorClass: 403 // For '?', if we are referring to condition, just have the edge point 404 // to the entire '?' expression. 405 if (cast<AbstractConditionalOperator>(Parent)->getCond() == S) 406 return PathDiagnosticLocation(Parent, SMgr, LC); 407 else 408 return PathDiagnosticLocation(S, SMgr, LC); 409 case Stmt::DoStmtClass: 410 return PathDiagnosticLocation(S, SMgr, LC); 411 case Stmt::ForStmtClass: 412 if (cast<ForStmt>(Parent)->getBody() == S) 413 return PathDiagnosticLocation(S, SMgr, LC); 414 break; 415 case Stmt::IfStmtClass: 416 if (cast<IfStmt>(Parent)->getCond() != S) 417 return PathDiagnosticLocation(S, SMgr, LC); 418 break; 419 case Stmt::ObjCForCollectionStmtClass: 420 if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S) 421 return PathDiagnosticLocation(S, SMgr, LC); 422 break; 423 case Stmt::WhileStmtClass: 424 if (cast<WhileStmt>(Parent)->getCond() != S) 425 return PathDiagnosticLocation(S, SMgr, LC); 426 break; 427 default: 428 break; 429 } 430 431 S = Parent; 432 } 433 434 assert(S && "Cannot have null Stmt for PathDiagnosticLocation"); 435 436 // Special case: DeclStmts can appear in for statement declarations, in which 437 // case the ForStmt is the context. 438 if (isa<DeclStmt>(S)) { 439 if (const Stmt *Parent = P.getParent(S)) { 440 switch (Parent->getStmtClass()) { 441 case Stmt::ForStmtClass: 442 case Stmt::ObjCForCollectionStmtClass: 443 return PathDiagnosticLocation(Parent, SMgr, LC); 444 default: 445 break; 446 } 447 } 448 } 449 else if (isa<BinaryOperator>(S)) { 450 // Special case: the binary operator represents the initialization 451 // code in a for statement (this can happen when the variable being 452 // initialized is an old variable. 453 if (const ForStmt *FS = 454 dyn_cast_or_null<ForStmt>(P.getParentIgnoreParens(S))) { 455 if (FS->getInit() == S) 456 return PathDiagnosticLocation(FS, SMgr, LC); 457 } 458 } 459 460 return PathDiagnosticLocation(S, SMgr, LC); 461} 462 463//===----------------------------------------------------------------------===// 464// "Visitors only" path diagnostic generation algorithm. 465//===----------------------------------------------------------------------===// 466static bool GenerateVisitorsOnlyPathDiagnostic(PathDiagnostic &PD, 467 PathDiagnosticBuilder &PDB, 468 const ExplodedNode *N, 469 ArrayRef<BugReporterVisitor *> visitors) { 470 // All path generation skips the very first node (the error node). 471 // This is because there is special handling for the end-of-path note. 472 N = N->getFirstPred(); 473 if (!N) 474 return true; 475 476 BugReport *R = PDB.getBugReport(); 477 while (const ExplodedNode *Pred = N->getFirstPred()) { 478 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 479 E = visitors.end(); 480 I != E; ++I) { 481 // Visit all the node pairs, but throw the path pieces away. 482 PathDiagnosticPiece *Piece = (*I)->VisitNode(N, Pred, PDB, *R); 483 delete Piece; 484 } 485 486 N = Pred; 487 } 488 489 return R->isValid(); 490} 491 492//===----------------------------------------------------------------------===// 493// "Minimal" path diagnostic generation algorithm. 494//===----------------------------------------------------------------------===// 495typedef std::pair<PathDiagnosticCallPiece*, const ExplodedNode*> StackDiagPair; 496typedef SmallVector<StackDiagPair, 6> StackDiagVector; 497 498static void updateStackPiecesWithMessage(PathDiagnosticPiece *P, 499 StackDiagVector &CallStack) { 500 // If the piece contains a special message, add it to all the call 501 // pieces on the active stack. 502 if (PathDiagnosticEventPiece *ep = 503 dyn_cast<PathDiagnosticEventPiece>(P)) { 504 505 if (ep->hasCallStackHint()) 506 for (StackDiagVector::iterator I = CallStack.begin(), 507 E = CallStack.end(); I != E; ++I) { 508 PathDiagnosticCallPiece *CP = I->first; 509 const ExplodedNode *N = I->second; 510 std::string stackMsg = ep->getCallStackMessage(N); 511 512 // The last message on the path to final bug is the most important 513 // one. Since we traverse the path backwards, do not add the message 514 // if one has been previously added. 515 if (!CP->hasCallStackMessage()) 516 CP->setCallStackMessage(stackMsg); 517 } 518 } 519} 520 521static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM); 522 523static bool GenerateMinimalPathDiagnostic(PathDiagnostic& PD, 524 PathDiagnosticBuilder &PDB, 525 const ExplodedNode *N, 526 LocationContextMap &LCM, 527 ArrayRef<BugReporterVisitor *> visitors) { 528 529 SourceManager& SMgr = PDB.getSourceManager(); 530 const LocationContext *LC = PDB.LC; 531 const ExplodedNode *NextNode = N->pred_empty() 532 ? NULL : *(N->pred_begin()); 533 534 StackDiagVector CallStack; 535 536 while (NextNode) { 537 N = NextNode; 538 PDB.LC = N->getLocationContext(); 539 NextNode = N->getFirstPred(); 540 541 ProgramPoint P = N->getLocation(); 542 543 do { 544 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 545 PathDiagnosticCallPiece *C = 546 PathDiagnosticCallPiece::construct(N, *CE, SMgr); 547 // Record the mapping from call piece to LocationContext. 548 LCM[&C->path] = CE->getCalleeContext(); 549 PD.getActivePath().push_front(C); 550 PD.pushActivePath(&C->path); 551 CallStack.push_back(StackDiagPair(C, N)); 552 break; 553 } 554 555 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 556 // Flush all locations, and pop the active path. 557 bool VisitedEntireCall = PD.isWithinCall(); 558 PD.popActivePath(); 559 560 // Either we just added a bunch of stuff to the top-level path, or 561 // we have a previous CallExitEnd. If the former, it means that the 562 // path terminated within a function call. We must then take the 563 // current contents of the active path and place it within 564 // a new PathDiagnosticCallPiece. 565 PathDiagnosticCallPiece *C; 566 if (VisitedEntireCall) { 567 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 568 } else { 569 const Decl *Caller = CE->getLocationContext()->getDecl(); 570 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 571 // Record the mapping from call piece to LocationContext. 572 LCM[&C->path] = CE->getCalleeContext(); 573 } 574 575 C->setCallee(*CE, SMgr); 576 if (!CallStack.empty()) { 577 assert(CallStack.back().first == C); 578 CallStack.pop_back(); 579 } 580 break; 581 } 582 583 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 584 const CFGBlock *Src = BE->getSrc(); 585 const CFGBlock *Dst = BE->getDst(); 586 const Stmt *T = Src->getTerminator(); 587 588 if (!T) 589 break; 590 591 PathDiagnosticLocation Start = 592 PathDiagnosticLocation::createBegin(T, SMgr, 593 N->getLocationContext()); 594 595 switch (T->getStmtClass()) { 596 default: 597 break; 598 599 case Stmt::GotoStmtClass: 600 case Stmt::IndirectGotoStmtClass: { 601 const Stmt *S = PathDiagnosticLocation::getNextStmt(N); 602 603 if (!S) 604 break; 605 606 std::string sbuf; 607 llvm::raw_string_ostream os(sbuf); 608 const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S); 609 610 os << "Control jumps to line " 611 << End.asLocation().getExpansionLineNumber(); 612 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 613 Start, End, os.str())); 614 break; 615 } 616 617 case Stmt::SwitchStmtClass: { 618 // Figure out what case arm we took. 619 std::string sbuf; 620 llvm::raw_string_ostream os(sbuf); 621 622 if (const Stmt *S = Dst->getLabel()) { 623 PathDiagnosticLocation End(S, SMgr, LC); 624 625 switch (S->getStmtClass()) { 626 default: 627 os << "No cases match in the switch statement. " 628 "Control jumps to line " 629 << End.asLocation().getExpansionLineNumber(); 630 break; 631 case Stmt::DefaultStmtClass: 632 os << "Control jumps to the 'default' case at line " 633 << End.asLocation().getExpansionLineNumber(); 634 break; 635 636 case Stmt::CaseStmtClass: { 637 os << "Control jumps to 'case "; 638 const CaseStmt *Case = cast<CaseStmt>(S); 639 const Expr *LHS = Case->getLHS()->IgnoreParenCasts(); 640 641 // Determine if it is an enum. 642 bool GetRawInt = true; 643 644 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS)) { 645 // FIXME: Maybe this should be an assertion. Are there cases 646 // were it is not an EnumConstantDecl? 647 const EnumConstantDecl *D = 648 dyn_cast<EnumConstantDecl>(DR->getDecl()); 649 650 if (D) { 651 GetRawInt = false; 652 os << *D; 653 } 654 } 655 656 if (GetRawInt) 657 os << LHS->EvaluateKnownConstInt(PDB.getASTContext()); 658 659 os << ":' at line " 660 << End.asLocation().getExpansionLineNumber(); 661 break; 662 } 663 } 664 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 665 Start, End, os.str())); 666 } 667 else { 668 os << "'Default' branch taken. "; 669 const PathDiagnosticLocation &End = PDB.ExecutionContinues(os, N); 670 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 671 Start, End, os.str())); 672 } 673 674 break; 675 } 676 677 case Stmt::BreakStmtClass: 678 case Stmt::ContinueStmtClass: { 679 std::string sbuf; 680 llvm::raw_string_ostream os(sbuf); 681 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 682 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 683 Start, End, os.str())); 684 break; 685 } 686 687 // Determine control-flow for ternary '?'. 688 case Stmt::BinaryConditionalOperatorClass: 689 case Stmt::ConditionalOperatorClass: { 690 std::string sbuf; 691 llvm::raw_string_ostream os(sbuf); 692 os << "'?' condition is "; 693 694 if (*(Src->succ_begin()+1) == Dst) 695 os << "false"; 696 else 697 os << "true"; 698 699 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 700 701 if (const Stmt *S = End.asStmt()) 702 End = PDB.getEnclosingStmtLocation(S); 703 704 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 705 Start, End, os.str())); 706 break; 707 } 708 709 // Determine control-flow for short-circuited '&&' and '||'. 710 case Stmt::BinaryOperatorClass: { 711 if (!PDB.supportsLogicalOpControlFlow()) 712 break; 713 714 const BinaryOperator *B = cast<BinaryOperator>(T); 715 std::string sbuf; 716 llvm::raw_string_ostream os(sbuf); 717 os << "Left side of '"; 718 719 if (B->getOpcode() == BO_LAnd) { 720 os << "&&" << "' is "; 721 722 if (*(Src->succ_begin()+1) == Dst) { 723 os << "false"; 724 PathDiagnosticLocation End(B->getLHS(), SMgr, LC); 725 PathDiagnosticLocation Start = 726 PathDiagnosticLocation::createOperatorLoc(B, SMgr); 727 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 728 Start, End, os.str())); 729 } 730 else { 731 os << "true"; 732 PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); 733 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 734 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 735 Start, End, os.str())); 736 } 737 } 738 else { 739 assert(B->getOpcode() == BO_LOr); 740 os << "||" << "' is "; 741 742 if (*(Src->succ_begin()+1) == Dst) { 743 os << "false"; 744 PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); 745 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 746 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 747 Start, End, os.str())); 748 } 749 else { 750 os << "true"; 751 PathDiagnosticLocation End(B->getLHS(), SMgr, LC); 752 PathDiagnosticLocation Start = 753 PathDiagnosticLocation::createOperatorLoc(B, SMgr); 754 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 755 Start, End, os.str())); 756 } 757 } 758 759 break; 760 } 761 762 case Stmt::DoStmtClass: { 763 if (*(Src->succ_begin()) == Dst) { 764 std::string sbuf; 765 llvm::raw_string_ostream os(sbuf); 766 767 os << "Loop condition is true. "; 768 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 769 770 if (const Stmt *S = End.asStmt()) 771 End = PDB.getEnclosingStmtLocation(S); 772 773 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 774 Start, End, os.str())); 775 } 776 else { 777 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 778 779 if (const Stmt *S = End.asStmt()) 780 End = PDB.getEnclosingStmtLocation(S); 781 782 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 783 Start, End, "Loop condition is false. Exiting loop")); 784 } 785 786 break; 787 } 788 789 case Stmt::WhileStmtClass: 790 case Stmt::ForStmtClass: { 791 if (*(Src->succ_begin()+1) == Dst) { 792 std::string sbuf; 793 llvm::raw_string_ostream os(sbuf); 794 795 os << "Loop condition is false. "; 796 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 797 if (const Stmt *S = End.asStmt()) 798 End = PDB.getEnclosingStmtLocation(S); 799 800 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 801 Start, End, os.str())); 802 } 803 else { 804 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 805 if (const Stmt *S = End.asStmt()) 806 End = PDB.getEnclosingStmtLocation(S); 807 808 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 809 Start, End, "Loop condition is true. Entering loop body")); 810 } 811 812 break; 813 } 814 815 case Stmt::IfStmtClass: { 816 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 817 818 if (const Stmt *S = End.asStmt()) 819 End = PDB.getEnclosingStmtLocation(S); 820 821 if (*(Src->succ_begin()+1) == Dst) 822 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 823 Start, End, "Taking false branch")); 824 else 825 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 826 Start, End, "Taking true branch")); 827 828 break; 829 } 830 } 831 } 832 } while(0); 833 834 if (NextNode) { 835 // Add diagnostic pieces from custom visitors. 836 BugReport *R = PDB.getBugReport(); 837 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 838 E = visitors.end(); 839 I != E; ++I) { 840 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 841 PD.getActivePath().push_front(p); 842 updateStackPiecesWithMessage(p, CallStack); 843 } 844 } 845 } 846 } 847 848 if (!PDB.getBugReport()->isValid()) 849 return false; 850 851 // After constructing the full PathDiagnostic, do a pass over it to compact 852 // PathDiagnosticPieces that occur within a macro. 853 CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager()); 854 return true; 855} 856 857//===----------------------------------------------------------------------===// 858// "Extensive" PathDiagnostic generation. 859//===----------------------------------------------------------------------===// 860 861static bool IsControlFlowExpr(const Stmt *S) { 862 const Expr *E = dyn_cast<Expr>(S); 863 864 if (!E) 865 return false; 866 867 E = E->IgnoreParenCasts(); 868 869 if (isa<AbstractConditionalOperator>(E)) 870 return true; 871 872 if (const BinaryOperator *B = dyn_cast<BinaryOperator>(E)) 873 if (B->isLogicalOp()) 874 return true; 875 876 return false; 877} 878 879namespace { 880class ContextLocation : public PathDiagnosticLocation { 881 bool IsDead; 882public: 883 ContextLocation(const PathDiagnosticLocation &L, bool isdead = false) 884 : PathDiagnosticLocation(L), IsDead(isdead) {} 885 886 void markDead() { IsDead = true; } 887 bool isDead() const { return IsDead; } 888}; 889 890static PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L, 891 const LocationContext *LC, 892 bool firstCharOnly = false) { 893 if (const Stmt *S = L.asStmt()) { 894 const Stmt *Original = S; 895 while (1) { 896 // Adjust the location for some expressions that are best referenced 897 // by one of their subexpressions. 898 switch (S->getStmtClass()) { 899 default: 900 break; 901 case Stmt::ParenExprClass: 902 case Stmt::GenericSelectionExprClass: 903 S = cast<Expr>(S)->IgnoreParens(); 904 firstCharOnly = true; 905 continue; 906 case Stmt::BinaryConditionalOperatorClass: 907 case Stmt::ConditionalOperatorClass: 908 S = cast<AbstractConditionalOperator>(S)->getCond(); 909 firstCharOnly = true; 910 continue; 911 case Stmt::ChooseExprClass: 912 S = cast<ChooseExpr>(S)->getCond(); 913 firstCharOnly = true; 914 continue; 915 case Stmt::BinaryOperatorClass: 916 S = cast<BinaryOperator>(S)->getLHS(); 917 firstCharOnly = true; 918 continue; 919 } 920 921 break; 922 } 923 924 if (S != Original) 925 L = PathDiagnosticLocation(S, L.getManager(), LC); 926 } 927 928 if (firstCharOnly) 929 L = PathDiagnosticLocation::createSingleLocation(L); 930 931 return L; 932} 933 934class EdgeBuilder { 935 std::vector<ContextLocation> CLocs; 936 typedef std::vector<ContextLocation>::iterator iterator; 937 PathDiagnostic &PD; 938 PathDiagnosticBuilder &PDB; 939 PathDiagnosticLocation PrevLoc; 940 941 bool IsConsumedExpr(const PathDiagnosticLocation &L); 942 943 bool containsLocation(const PathDiagnosticLocation &Container, 944 const PathDiagnosticLocation &Containee); 945 946 PathDiagnosticLocation getContextLocation(const PathDiagnosticLocation &L); 947 948 949 950 void popLocation() { 951 if (!CLocs.back().isDead() && CLocs.back().asLocation().isFileID()) { 952 // For contexts, we only one the first character as the range. 953 rawAddEdge(cleanUpLocation(CLocs.back(), PDB.LC, true)); 954 } 955 CLocs.pop_back(); 956 } 957 958public: 959 EdgeBuilder(PathDiagnostic &pd, PathDiagnosticBuilder &pdb) 960 : PD(pd), PDB(pdb) { 961 962 // If the PathDiagnostic already has pieces, add the enclosing statement 963 // of the first piece as a context as well. 964 if (!PD.path.empty()) { 965 PrevLoc = (*PD.path.begin())->getLocation(); 966 967 if (const Stmt *S = PrevLoc.asStmt()) 968 addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 969 } 970 } 971 972 ~EdgeBuilder() { 973 while (!CLocs.empty()) popLocation(); 974 975 // Finally, add an initial edge from the start location of the first 976 // statement (if it doesn't already exist). 977 PathDiagnosticLocation L = PathDiagnosticLocation::createDeclBegin( 978 PDB.LC, 979 PDB.getSourceManager()); 980 if (L.isValid()) 981 rawAddEdge(L); 982 } 983 984 void flushLocations() { 985 while (!CLocs.empty()) 986 popLocation(); 987 PrevLoc = PathDiagnosticLocation(); 988 } 989 990 void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false, 991 bool IsPostJump = false); 992 993 void rawAddEdge(PathDiagnosticLocation NewLoc); 994 995 void addContext(const Stmt *S); 996 void addContext(const PathDiagnosticLocation &L); 997 void addExtendedContext(const Stmt *S); 998}; 999} // end anonymous namespace 1000 1001 1002PathDiagnosticLocation 1003EdgeBuilder::getContextLocation(const PathDiagnosticLocation &L) { 1004 if (const Stmt *S = L.asStmt()) { 1005 if (IsControlFlowExpr(S)) 1006 return L; 1007 1008 return PDB.getEnclosingStmtLocation(S); 1009 } 1010 1011 return L; 1012} 1013 1014bool EdgeBuilder::containsLocation(const PathDiagnosticLocation &Container, 1015 const PathDiagnosticLocation &Containee) { 1016 1017 if (Container == Containee) 1018 return true; 1019 1020 if (Container.asDecl()) 1021 return true; 1022 1023 if (const Stmt *S = Containee.asStmt()) 1024 if (const Stmt *ContainerS = Container.asStmt()) { 1025 while (S) { 1026 if (S == ContainerS) 1027 return true; 1028 S = PDB.getParent(S); 1029 } 1030 return false; 1031 } 1032 1033 // Less accurate: compare using source ranges. 1034 SourceRange ContainerR = Container.asRange(); 1035 SourceRange ContaineeR = Containee.asRange(); 1036 1037 SourceManager &SM = PDB.getSourceManager(); 1038 SourceLocation ContainerRBeg = SM.getExpansionLoc(ContainerR.getBegin()); 1039 SourceLocation ContainerREnd = SM.getExpansionLoc(ContainerR.getEnd()); 1040 SourceLocation ContaineeRBeg = SM.getExpansionLoc(ContaineeR.getBegin()); 1041 SourceLocation ContaineeREnd = SM.getExpansionLoc(ContaineeR.getEnd()); 1042 1043 unsigned ContainerBegLine = SM.getExpansionLineNumber(ContainerRBeg); 1044 unsigned ContainerEndLine = SM.getExpansionLineNumber(ContainerREnd); 1045 unsigned ContaineeBegLine = SM.getExpansionLineNumber(ContaineeRBeg); 1046 unsigned ContaineeEndLine = SM.getExpansionLineNumber(ContaineeREnd); 1047 1048 assert(ContainerBegLine <= ContainerEndLine); 1049 assert(ContaineeBegLine <= ContaineeEndLine); 1050 1051 return (ContainerBegLine <= ContaineeBegLine && 1052 ContainerEndLine >= ContaineeEndLine && 1053 (ContainerBegLine != ContaineeBegLine || 1054 SM.getExpansionColumnNumber(ContainerRBeg) <= 1055 SM.getExpansionColumnNumber(ContaineeRBeg)) && 1056 (ContainerEndLine != ContaineeEndLine || 1057 SM.getExpansionColumnNumber(ContainerREnd) >= 1058 SM.getExpansionColumnNumber(ContaineeREnd))); 1059} 1060 1061void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) { 1062 if (!PrevLoc.isValid()) { 1063 PrevLoc = NewLoc; 1064 return; 1065 } 1066 1067 const PathDiagnosticLocation &NewLocClean = cleanUpLocation(NewLoc, PDB.LC); 1068 const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc, PDB.LC); 1069 1070 if (PrevLocClean.asLocation().isInvalid()) { 1071 PrevLoc = NewLoc; 1072 return; 1073 } 1074 1075 if (NewLocClean.asLocation() == PrevLocClean.asLocation()) 1076 return; 1077 1078 // FIXME: Ignore intra-macro edges for now. 1079 if (NewLocClean.asLocation().getExpansionLoc() == 1080 PrevLocClean.asLocation().getExpansionLoc()) 1081 return; 1082 1083 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(NewLocClean, PrevLocClean)); 1084 PrevLoc = NewLoc; 1085} 1086 1087void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd, 1088 bool IsPostJump) { 1089 1090 if (!alwaysAdd && NewLoc.asLocation().isMacroID()) 1091 return; 1092 1093 const PathDiagnosticLocation &CLoc = getContextLocation(NewLoc); 1094 1095 while (!CLocs.empty()) { 1096 ContextLocation &TopContextLoc = CLocs.back(); 1097 1098 // Is the top location context the same as the one for the new location? 1099 if (TopContextLoc == CLoc) { 1100 if (alwaysAdd) { 1101 if (IsConsumedExpr(TopContextLoc)) 1102 TopContextLoc.markDead(); 1103 1104 rawAddEdge(NewLoc); 1105 } 1106 1107 if (IsPostJump) 1108 TopContextLoc.markDead(); 1109 return; 1110 } 1111 1112 if (containsLocation(TopContextLoc, CLoc)) { 1113 if (alwaysAdd) { 1114 rawAddEdge(NewLoc); 1115 1116 if (IsConsumedExpr(CLoc)) { 1117 CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/true)); 1118 return; 1119 } 1120 } 1121 1122 CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/IsPostJump)); 1123 return; 1124 } 1125 1126 // Context does not contain the location. Flush it. 1127 popLocation(); 1128 } 1129 1130 // If we reach here, there is no enclosing context. Just add the edge. 1131 rawAddEdge(NewLoc); 1132} 1133 1134bool EdgeBuilder::IsConsumedExpr(const PathDiagnosticLocation &L) { 1135 if (const Expr *X = dyn_cast_or_null<Expr>(L.asStmt())) 1136 return PDB.getParentMap().isConsumedExpr(X) && !IsControlFlowExpr(X); 1137 1138 return false; 1139} 1140 1141void EdgeBuilder::addExtendedContext(const Stmt *S) { 1142 if (!S) 1143 return; 1144 1145 const Stmt *Parent = PDB.getParent(S); 1146 while (Parent) { 1147 if (isa<CompoundStmt>(Parent)) 1148 Parent = PDB.getParent(Parent); 1149 else 1150 break; 1151 } 1152 1153 if (Parent) { 1154 switch (Parent->getStmtClass()) { 1155 case Stmt::DoStmtClass: 1156 case Stmt::ObjCAtSynchronizedStmtClass: 1157 addContext(Parent); 1158 default: 1159 break; 1160 } 1161 } 1162 1163 addContext(S); 1164} 1165 1166void EdgeBuilder::addContext(const Stmt *S) { 1167 if (!S) 1168 return; 1169 1170 PathDiagnosticLocation L(S, PDB.getSourceManager(), PDB.LC); 1171 addContext(L); 1172} 1173 1174void EdgeBuilder::addContext(const PathDiagnosticLocation &L) { 1175 while (!CLocs.empty()) { 1176 const PathDiagnosticLocation &TopContextLoc = CLocs.back(); 1177 1178 // Is the top location context the same as the one for the new location? 1179 if (TopContextLoc == L) 1180 return; 1181 1182 if (containsLocation(TopContextLoc, L)) { 1183 CLocs.push_back(L); 1184 return; 1185 } 1186 1187 // Context does not contain the location. Flush it. 1188 popLocation(); 1189 } 1190 1191 CLocs.push_back(L); 1192} 1193 1194// Cone-of-influence: support the reverse propagation of "interesting" symbols 1195// and values by tracing interesting calculations backwards through evaluated 1196// expressions along a path. This is probably overly complicated, but the idea 1197// is that if an expression computed an "interesting" value, the child 1198// expressions are are also likely to be "interesting" as well (which then 1199// propagates to the values they in turn compute). This reverse propagation 1200// is needed to track interesting correlations across function call boundaries, 1201// where formal arguments bind to actual arguments, etc. This is also needed 1202// because the constraint solver sometimes simplifies certain symbolic values 1203// into constants when appropriate, and this complicates reasoning about 1204// interesting values. 1205typedef llvm::DenseSet<const Expr *> InterestingExprs; 1206 1207static void reversePropagateIntererstingSymbols(BugReport &R, 1208 InterestingExprs &IE, 1209 const ProgramState *State, 1210 const Expr *Ex, 1211 const LocationContext *LCtx) { 1212 SVal V = State->getSVal(Ex, LCtx); 1213 if (!(R.isInteresting(V) || IE.count(Ex))) 1214 return; 1215 1216 switch (Ex->getStmtClass()) { 1217 default: 1218 if (!isa<CastExpr>(Ex)) 1219 break; 1220 // Fall through. 1221 case Stmt::BinaryOperatorClass: 1222 case Stmt::UnaryOperatorClass: { 1223 for (Stmt::const_child_iterator CI = Ex->child_begin(), 1224 CE = Ex->child_end(); 1225 CI != CE; ++CI) { 1226 if (const Expr *child = dyn_cast_or_null<Expr>(*CI)) { 1227 IE.insert(child); 1228 SVal ChildV = State->getSVal(child, LCtx); 1229 R.markInteresting(ChildV); 1230 } 1231 break; 1232 } 1233 } 1234 } 1235 1236 R.markInteresting(V); 1237} 1238 1239static void reversePropagateInterestingSymbols(BugReport &R, 1240 InterestingExprs &IE, 1241 const ProgramState *State, 1242 const LocationContext *CalleeCtx, 1243 const LocationContext *CallerCtx) 1244{ 1245 // FIXME: Handle non-CallExpr-based CallEvents. 1246 const StackFrameContext *Callee = CalleeCtx->getCurrentStackFrame(); 1247 const Stmt *CallSite = Callee->getCallSite(); 1248 if (const CallExpr *CE = dyn_cast_or_null<CallExpr>(CallSite)) { 1249 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CalleeCtx->getDecl())) { 1250 FunctionDecl::param_const_iterator PI = FD->param_begin(), 1251 PE = FD->param_end(); 1252 CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end(); 1253 for (; AI != AE && PI != PE; ++AI, ++PI) { 1254 if (const Expr *ArgE = *AI) { 1255 if (const ParmVarDecl *PD = *PI) { 1256 Loc LV = State->getLValue(PD, CalleeCtx); 1257 if (R.isInteresting(LV) || R.isInteresting(State->getRawSVal(LV))) 1258 IE.insert(ArgE); 1259 } 1260 } 1261 } 1262 } 1263 } 1264} 1265 1266//===----------------------------------------------------------------------===// 1267// Functions for determining if a loop was executed 0 times. 1268//===----------------------------------------------------------------------===// 1269 1270static bool isLoop(const Stmt *Term) { 1271 switch (Term->getStmtClass()) { 1272 case Stmt::ForStmtClass: 1273 case Stmt::WhileStmtClass: 1274 case Stmt::ObjCForCollectionStmtClass: 1275 return true; 1276 default: 1277 // Note that we intentionally do not include do..while here. 1278 return false; 1279 } 1280} 1281 1282static bool isJumpToFalseBranch(const BlockEdge *BE) { 1283 const CFGBlock *Src = BE->getSrc(); 1284 assert(Src->succ_size() == 2); 1285 return (*(Src->succ_begin()+1) == BE->getDst()); 1286} 1287 1288/// Return true if the terminator is a loop and the destination is the 1289/// false branch. 1290static bool isLoopJumpPastBody(const Stmt *Term, const BlockEdge *BE) { 1291 if (!isLoop(Term)) 1292 return false; 1293 1294 // Did we take the false branch? 1295 return isJumpToFalseBranch(BE); 1296} 1297 1298static bool isContainedByStmt(ParentMap &PM, const Stmt *S, const Stmt *SubS) { 1299 while (SubS) { 1300 if (SubS == S) 1301 return true; 1302 SubS = PM.getParent(SubS); 1303 } 1304 return false; 1305} 1306 1307static const Stmt *getStmtBeforeCond(ParentMap &PM, const Stmt *Term, 1308 const ExplodedNode *N) { 1309 while (N) { 1310 Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>(); 1311 if (SP) { 1312 const Stmt *S = SP->getStmt(); 1313 if (!isContainedByStmt(PM, Term, S)) 1314 return S; 1315 } 1316 N = N->getFirstPred(); 1317 } 1318 return 0; 1319} 1320 1321static bool isInLoopBody(ParentMap &PM, const Stmt *S, const Stmt *Term) { 1322 const Stmt *LoopBody = 0; 1323 switch (Term->getStmtClass()) { 1324 case Stmt::ForStmtClass: { 1325 const ForStmt *FS = cast<ForStmt>(Term); 1326 if (isContainedByStmt(PM, FS->getInc(), S)) 1327 return true; 1328 LoopBody = FS->getBody(); 1329 break; 1330 } 1331 case Stmt::ObjCForCollectionStmtClass: { 1332 const ObjCForCollectionStmt *FC = cast<ObjCForCollectionStmt>(Term); 1333 LoopBody = FC->getBody(); 1334 break; 1335 } 1336 case Stmt::WhileStmtClass: 1337 LoopBody = cast<WhileStmt>(Term)->getBody(); 1338 break; 1339 default: 1340 return false; 1341 } 1342 return isContainedByStmt(PM, LoopBody, S); 1343} 1344 1345//===----------------------------------------------------------------------===// 1346// Top-level logic for generating extensive path diagnostics. 1347//===----------------------------------------------------------------------===// 1348 1349static bool GenerateExtensivePathDiagnostic(PathDiagnostic& PD, 1350 PathDiagnosticBuilder &PDB, 1351 const ExplodedNode *N, 1352 LocationContextMap &LCM, 1353 ArrayRef<BugReporterVisitor *> visitors) { 1354 EdgeBuilder EB(PD, PDB); 1355 const SourceManager& SM = PDB.getSourceManager(); 1356 StackDiagVector CallStack; 1357 InterestingExprs IE; 1358 1359 const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin()); 1360 while (NextNode) { 1361 N = NextNode; 1362 NextNode = N->getFirstPred(); 1363 ProgramPoint P = N->getLocation(); 1364 1365 do { 1366 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1367 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1368 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1369 N->getState().getPtr(), Ex, 1370 N->getLocationContext()); 1371 } 1372 1373 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1374 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1375 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1376 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1377 N->getState().getPtr(), Ex, 1378 N->getLocationContext()); 1379 } 1380 1381 PathDiagnosticCallPiece *C = 1382 PathDiagnosticCallPiece::construct(N, *CE, SM); 1383 LCM[&C->path] = CE->getCalleeContext(); 1384 1385 EB.addEdge(C->callReturn, /*AlwaysAdd=*/true, /*IsPostJump=*/true); 1386 EB.flushLocations(); 1387 1388 PD.getActivePath().push_front(C); 1389 PD.pushActivePath(&C->path); 1390 CallStack.push_back(StackDiagPair(C, N)); 1391 break; 1392 } 1393 1394 // Pop the call hierarchy if we are done walking the contents 1395 // of a function call. 1396 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1397 // Add an edge to the start of the function. 1398 const Decl *D = CE->getCalleeContext()->getDecl(); 1399 PathDiagnosticLocation pos = 1400 PathDiagnosticLocation::createBegin(D, SM); 1401 EB.addEdge(pos); 1402 1403 // Flush all locations, and pop the active path. 1404 bool VisitedEntireCall = PD.isWithinCall(); 1405 EB.flushLocations(); 1406 PD.popActivePath(); 1407 PDB.LC = N->getLocationContext(); 1408 1409 // Either we just added a bunch of stuff to the top-level path, or 1410 // we have a previous CallExitEnd. If the former, it means that the 1411 // path terminated within a function call. We must then take the 1412 // current contents of the active path and place it within 1413 // a new PathDiagnosticCallPiece. 1414 PathDiagnosticCallPiece *C; 1415 if (VisitedEntireCall) { 1416 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 1417 } else { 1418 const Decl *Caller = CE->getLocationContext()->getDecl(); 1419 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1420 LCM[&C->path] = CE->getCalleeContext(); 1421 } 1422 1423 C->setCallee(*CE, SM); 1424 EB.addContext(C->getLocation()); 1425 1426 if (!CallStack.empty()) { 1427 assert(CallStack.back().first == C); 1428 CallStack.pop_back(); 1429 } 1430 break; 1431 } 1432 1433 // Note that is important that we update the LocationContext 1434 // after looking at CallExits. CallExit basically adds an 1435 // edge in the *caller*, so we don't want to update the LocationContext 1436 // too soon. 1437 PDB.LC = N->getLocationContext(); 1438 1439 // Block edges. 1440 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1441 // Does this represent entering a call? If so, look at propagating 1442 // interesting symbols across call boundaries. 1443 if (NextNode) { 1444 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1445 const LocationContext *CalleeCtx = PDB.LC; 1446 if (CallerCtx != CalleeCtx) { 1447 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1448 N->getState().getPtr(), 1449 CalleeCtx, CallerCtx); 1450 } 1451 } 1452 1453 // Are we jumping to the head of a loop? Add a special diagnostic. 1454 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1455 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1456 const CompoundStmt *CS = NULL; 1457 1458 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1459 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1460 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1461 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1462 1463 PathDiagnosticEventPiece *p = 1464 new PathDiagnosticEventPiece(L, 1465 "Looping back to the head of the loop"); 1466 p->setPrunable(true); 1467 1468 EB.addEdge(p->getLocation(), true); 1469 PD.getActivePath().push_front(p); 1470 1471 if (CS) { 1472 PathDiagnosticLocation BL = 1473 PathDiagnosticLocation::createEndBrace(CS, SM); 1474 EB.addEdge(BL); 1475 } 1476 } 1477 1478 const CFGBlock *BSrc = BE->getSrc(); 1479 ParentMap &PM = PDB.getParentMap(); 1480 1481 if (const Stmt *Term = BSrc->getTerminator()) { 1482 // Are we jumping past the loop body without ever executing the 1483 // loop (because the condition was false)? 1484 if (isLoopJumpPastBody(Term, &*BE) && 1485 !isInLoopBody(PM, 1486 getStmtBeforeCond(PM, 1487 BSrc->getTerminatorCondition(), 1488 N), 1489 Term)) { 1490 PathDiagnosticLocation L(Term, SM, PDB.LC); 1491 PathDiagnosticEventPiece *PE = 1492 new PathDiagnosticEventPiece(L, "Loop body executed 0 times"); 1493 PE->setPrunable(true); 1494 1495 EB.addEdge(PE->getLocation(), true); 1496 PD.getActivePath().push_front(PE); 1497 } 1498 1499 // In any case, add the terminator as the current statement 1500 // context for control edges. 1501 EB.addContext(Term); 1502 } 1503 1504 break; 1505 } 1506 1507 if (Optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) { 1508 Optional<CFGElement> First = BE->getFirstElement(); 1509 if (Optional<CFGStmt> S = First ? First->getAs<CFGStmt>() : None) { 1510 const Stmt *stmt = S->getStmt(); 1511 if (IsControlFlowExpr(stmt)) { 1512 // Add the proper context for '&&', '||', and '?'. 1513 EB.addContext(stmt); 1514 } 1515 else 1516 EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt()); 1517 } 1518 1519 break; 1520 } 1521 1522 1523 } while (0); 1524 1525 if (!NextNode) 1526 continue; 1527 1528 // Add pieces from custom visitors. 1529 BugReport *R = PDB.getBugReport(); 1530 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1531 E = visitors.end(); 1532 I != E; ++I) { 1533 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 1534 const PathDiagnosticLocation &Loc = p->getLocation(); 1535 EB.addEdge(Loc, true); 1536 PD.getActivePath().push_front(p); 1537 updateStackPiecesWithMessage(p, CallStack); 1538 1539 if (const Stmt *S = Loc.asStmt()) 1540 EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 1541 } 1542 } 1543 } 1544 1545 return PDB.getBugReport()->isValid(); 1546} 1547 1548/// \brief Adds a sanitized control-flow diagnostic edge to a path. 1549static void addEdgeToPath(PathPieces &path, 1550 PathDiagnosticLocation &PrevLoc, 1551 PathDiagnosticLocation NewLoc, 1552 const LocationContext *LC) { 1553 if (!NewLoc.isValid()) 1554 return; 1555 1556 SourceLocation NewLocL = NewLoc.asLocation(); 1557 if (NewLocL.isInvalid() || NewLocL.isMacroID()) 1558 return; 1559 1560 if (!PrevLoc.isValid() || !PrevLoc.asLocation().isValid()) { 1561 PrevLoc = NewLoc; 1562 return; 1563 } 1564 1565 // FIXME: ignore intra-macro edges for now. 1566 if (NewLoc.asLocation().getExpansionLoc() == 1567 PrevLoc.asLocation().getExpansionLoc()) 1568 return; 1569 1570 path.push_front(new PathDiagnosticControlFlowPiece(NewLoc, 1571 PrevLoc)); 1572 PrevLoc = NewLoc; 1573} 1574 1575/// A customized wrapper for CFGBlock::getTerminatorCondition() 1576/// which returns the element for ObjCForCollectionStmts. 1577static const Stmt *getTerminatorCondition(const CFGBlock *B) { 1578 const Stmt *S = B->getTerminatorCondition(); 1579 if (const ObjCForCollectionStmt *FS = 1580 dyn_cast_or_null<ObjCForCollectionStmt>(S)) 1581 return FS->getElement(); 1582 return S; 1583} 1584 1585static const char *StrEnteringLoop = "Entering loop body"; 1586static const char *StrLoopBodyZero = "Loop body executed 0 times"; 1587 1588static bool 1589GenerateAlternateExtensivePathDiagnostic(PathDiagnostic& PD, 1590 PathDiagnosticBuilder &PDB, 1591 const ExplodedNode *N, 1592 LocationContextMap &LCM, 1593 ArrayRef<BugReporterVisitor *> visitors) { 1594 1595 BugReport *report = PDB.getBugReport(); 1596 const SourceManager& SM = PDB.getSourceManager(); 1597 StackDiagVector CallStack; 1598 InterestingExprs IE; 1599 1600 PathDiagnosticLocation PrevLoc = PD.getLocation(); 1601 1602 const ExplodedNode *NextNode = N->getFirstPred(); 1603 while (NextNode) { 1604 N = NextNode; 1605 NextNode = N->getFirstPred(); 1606 ProgramPoint P = N->getLocation(); 1607 1608 do { 1609 // Have we encountered an entrance to a call? It may be 1610 // the case that we have not encountered a matching 1611 // call exit before this point. This means that the path 1612 // terminated within the call itself. 1613 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1614 // Add an edge to the start of the function. 1615 const StackFrameContext *CalleeLC = CE->getCalleeContext(); 1616 const Decl *D = CalleeLC->getDecl(); 1617 addEdgeToPath(PD.getActivePath(), PrevLoc, 1618 PathDiagnosticLocation::createBegin(D, SM), 1619 CalleeLC); 1620 1621 // Did we visit an entire call? 1622 bool VisitedEntireCall = PD.isWithinCall(); 1623 PD.popActivePath(); 1624 1625 PathDiagnosticCallPiece *C; 1626 if (VisitedEntireCall) { 1627 PathDiagnosticPiece *P = PD.getActivePath().front().getPtr(); 1628 C = cast<PathDiagnosticCallPiece>(P); 1629 } else { 1630 const Decl *Caller = CE->getLocationContext()->getDecl(); 1631 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1632 1633 // Since we just transferred the path over to the call piece, 1634 // reset the mapping from active to location context. 1635 assert(PD.getActivePath().size() == 1 && 1636 PD.getActivePath().front() == C); 1637 LCM[&PD.getActivePath()] = 0; 1638 1639 // Record the location context mapping for the path within 1640 // the call. 1641 assert(LCM[&C->path] == 0 || 1642 LCM[&C->path] == CE->getCalleeContext()); 1643 LCM[&C->path] = CE->getCalleeContext(); 1644 1645 // If this is the first item in the active path, record 1646 // the new mapping from active path to location context. 1647 const LocationContext *&NewLC = LCM[&PD.getActivePath()]; 1648 if (!NewLC) 1649 NewLC = N->getLocationContext(); 1650 1651 PDB.LC = NewLC; 1652 } 1653 C->setCallee(*CE, SM); 1654 1655 // Update the previous location in the active path. 1656 PrevLoc = C->getLocation(); 1657 1658 if (!CallStack.empty()) { 1659 assert(CallStack.back().first == C); 1660 CallStack.pop_back(); 1661 } 1662 break; 1663 } 1664 1665 // Query the location context here and the previous location 1666 // as processing CallEnter may change the active path. 1667 PDB.LC = N->getLocationContext(); 1668 1669 // Record the mapping from the active path to the location 1670 // context. 1671 assert(!LCM[&PD.getActivePath()] || 1672 LCM[&PD.getActivePath()] == PDB.LC); 1673 LCM[&PD.getActivePath()] = PDB.LC; 1674 1675 // Have we encountered an exit from a function call? 1676 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1677 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1678 // Propagate the interesting symbols accordingly. 1679 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1680 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1681 N->getState().getPtr(), Ex, 1682 N->getLocationContext()); 1683 } 1684 1685 // We are descending into a call (backwards). Construct 1686 // a new call piece to contain the path pieces for that call. 1687 PathDiagnosticCallPiece *C = 1688 PathDiagnosticCallPiece::construct(N, *CE, SM); 1689 1690 // Record the location context for this call piece. 1691 LCM[&C->path] = CE->getCalleeContext(); 1692 1693 // Add the edge to the return site. 1694 addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn, PDB.LC); 1695 PD.getActivePath().push_front(C); 1696 PrevLoc.invalidate(); 1697 1698 // Make the contents of the call the active path for now. 1699 PD.pushActivePath(&C->path); 1700 CallStack.push_back(StackDiagPair(C, N)); 1701 break; 1702 } 1703 1704 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1705 // For expressions, make sure we propagate the 1706 // interesting symbols correctly. 1707 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1708 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1709 N->getState().getPtr(), Ex, 1710 N->getLocationContext()); 1711 1712 // Add an edge. If this is an ObjCForCollectionStmt do 1713 // not add an edge here as it appears in the CFG both 1714 // as a terminator and as a terminator condition. 1715 if (!isa<ObjCForCollectionStmt>(PS->getStmt())) { 1716 PathDiagnosticLocation L = 1717 PathDiagnosticLocation(PS->getStmt(), SM, PDB.LC); 1718 addEdgeToPath(PD.getActivePath(), PrevLoc, L, PDB.LC); 1719 } 1720 break; 1721 } 1722 1723 // Block edges. 1724 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1725 // Does this represent entering a call? If so, look at propagating 1726 // interesting symbols across call boundaries. 1727 if (NextNode) { 1728 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1729 const LocationContext *CalleeCtx = PDB.LC; 1730 if (CallerCtx != CalleeCtx) { 1731 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1732 N->getState().getPtr(), 1733 CalleeCtx, CallerCtx); 1734 } 1735 } 1736 1737 // Are we jumping to the head of a loop? Add a special diagnostic. 1738 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1739 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1740 const CompoundStmt *CS = NULL; 1741 1742 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1743 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1744 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1745 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1746 else if (const ObjCForCollectionStmt *OFS = 1747 dyn_cast<ObjCForCollectionStmt>(Loop)) { 1748 CS = dyn_cast<CompoundStmt>(OFS->getBody()); 1749 } 1750 1751 PathDiagnosticEventPiece *p = 1752 new PathDiagnosticEventPiece(L, "Looping back to the head " 1753 "of the loop"); 1754 p->setPrunable(true); 1755 1756 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), PDB.LC); 1757 PD.getActivePath().push_front(p); 1758 1759 if (CS) { 1760 addEdgeToPath(PD.getActivePath(), PrevLoc, 1761 PathDiagnosticLocation::createEndBrace(CS, SM), 1762 PDB.LC); 1763 } 1764 } 1765 1766 const CFGBlock *BSrc = BE->getSrc(); 1767 ParentMap &PM = PDB.getParentMap(); 1768 1769 if (const Stmt *Term = BSrc->getTerminator()) { 1770 // Are we jumping past the loop body without ever executing the 1771 // loop (because the condition was false)? 1772 if (isLoop(Term)) { 1773 const Stmt *TermCond = getTerminatorCondition(BSrc); 1774 bool IsInLoopBody = 1775 isInLoopBody(PM, getStmtBeforeCond(PM, TermCond, N), Term); 1776 1777 const char *str = 0; 1778 1779 if (isJumpToFalseBranch(&*BE)) { 1780 if (!IsInLoopBody) { 1781 str = StrLoopBodyZero; 1782 } 1783 } 1784 else { 1785 str = StrEnteringLoop; 1786 } 1787 1788 if (str) { 1789 PathDiagnosticLocation L(TermCond ? TermCond : Term, SM, PDB.LC); 1790 PathDiagnosticEventPiece *PE = 1791 new PathDiagnosticEventPiece(L, str); 1792 PE->setPrunable(true); 1793 addEdgeToPath(PD.getActivePath(), PrevLoc, 1794 PE->getLocation(), PDB.LC); 1795 PD.getActivePath().push_front(PE); 1796 } 1797 } 1798 else if (isa<BreakStmt>(Term) || isa<ContinueStmt>(Term) || 1799 isa<GotoStmt>(Term)) { 1800 PathDiagnosticLocation L(Term, SM, PDB.LC); 1801 addEdgeToPath(PD.getActivePath(), PrevLoc, L, PDB.LC); 1802 } 1803 } 1804 break; 1805 } 1806 } while (0); 1807 1808 if (!NextNode) 1809 continue; 1810 1811 // Add pieces from custom visitors. 1812 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1813 E = visitors.end(); 1814 I != E; ++I) { 1815 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *report)) { 1816 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), PDB.LC); 1817 PD.getActivePath().push_front(p); 1818 updateStackPiecesWithMessage(p, CallStack); 1819 } 1820 } 1821 } 1822 1823 return report->isValid(); 1824} 1825 1826static const Stmt *getLocStmt(PathDiagnosticLocation L) { 1827 if (!L.isValid()) 1828 return 0; 1829 return L.asStmt(); 1830} 1831 1832static const Stmt *getStmtParent(const Stmt *S, ParentMap &PM) { 1833 if (!S) 1834 return 0; 1835 1836 while (true) { 1837 S = PM.getParentIgnoreParens(S); 1838 1839 if (!S) 1840 break; 1841 1842 if (isa<ExprWithCleanups>(S) || 1843 isa<CXXBindTemporaryExpr>(S) || 1844 isa<SubstNonTypeTemplateParmExpr>(S)) 1845 continue; 1846 1847 break; 1848 } 1849 1850 return S; 1851} 1852 1853static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) { 1854 switch (S->getStmtClass()) { 1855 case Stmt::BinaryOperatorClass: { 1856 const BinaryOperator *BO = cast<BinaryOperator>(S); 1857 if (!BO->isLogicalOp()) 1858 return false; 1859 return BO->getLHS() == Cond || BO->getRHS() == Cond; 1860 } 1861 case Stmt::IfStmtClass: 1862 return cast<IfStmt>(S)->getCond() == Cond; 1863 case Stmt::ForStmtClass: 1864 return cast<ForStmt>(S)->getCond() == Cond; 1865 case Stmt::WhileStmtClass: 1866 return cast<WhileStmt>(S)->getCond() == Cond; 1867 case Stmt::DoStmtClass: 1868 return cast<DoStmt>(S)->getCond() == Cond; 1869 case Stmt::ChooseExprClass: 1870 return cast<ChooseExpr>(S)->getCond() == Cond; 1871 case Stmt::IndirectGotoStmtClass: 1872 return cast<IndirectGotoStmt>(S)->getTarget() == Cond; 1873 case Stmt::SwitchStmtClass: 1874 return cast<SwitchStmt>(S)->getCond() == Cond; 1875 case Stmt::BinaryConditionalOperatorClass: 1876 return cast<BinaryConditionalOperator>(S)->getCond() == Cond; 1877 case Stmt::ConditionalOperatorClass: { 1878 const ConditionalOperator *CO = cast<ConditionalOperator>(S); 1879 return CO->getCond() == Cond || 1880 CO->getLHS() == Cond || 1881 CO->getRHS() == Cond; 1882 } 1883 case Stmt::ObjCForCollectionStmtClass: 1884 return cast<ObjCForCollectionStmt>(S)->getElement() == Cond; 1885 default: 1886 return false; 1887 } 1888} 1889 1890static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) { 1891 const ForStmt *FS = dyn_cast<ForStmt>(FL); 1892 if (!FS) 1893 return false; 1894 return FS->getInc() == S || FS->getInit() == S; 1895} 1896 1897typedef llvm::DenseSet<const PathDiagnosticCallPiece *> 1898 OptimizedCallsSet; 1899 1900void PathPieces::dump() const { 1901 unsigned index = 0; 1902 for (PathPieces::const_iterator I = begin(), E = end(); I != E; ++I ) { 1903 llvm::errs() << "[" << index++ << "]"; 1904 1905 switch ((*I)->getKind()) { 1906 case PathDiagnosticPiece::Call: 1907 llvm::errs() << " CALL\n--------------\n"; 1908 1909 if (const Stmt *SLoc = getLocStmt((*I)->getLocation())) { 1910 SLoc->dump(); 1911 } else { 1912 const PathDiagnosticCallPiece *Call = cast<PathDiagnosticCallPiece>(*I); 1913 if (const NamedDecl *ND = dyn_cast<NamedDecl>(Call->getCallee())) 1914 llvm::errs() << *ND << "\n"; 1915 } 1916 break; 1917 case PathDiagnosticPiece::Event: 1918 llvm::errs() << " EVENT\n--------------\n"; 1919 llvm::errs() << (*I)->getString() << "\n"; 1920 if (const Stmt *SLoc = getLocStmt((*I)->getLocation())) { 1921 llvm::errs() << " ---- at ----\n"; 1922 SLoc->dump(); 1923 } 1924 break; 1925 case PathDiagnosticPiece::Macro: 1926 llvm::errs() << " MACRO\n--------------\n"; 1927 // FIXME: print which macro is being invoked. 1928 break; 1929 case PathDiagnosticPiece::ControlFlow: { 1930 const PathDiagnosticControlFlowPiece *CP = 1931 cast<PathDiagnosticControlFlowPiece>(*I); 1932 llvm::errs() << " CONTROL\n--------------\n"; 1933 1934 if (const Stmt *s1Start = getLocStmt(CP->getStartLocation())) 1935 s1Start->dump(); 1936 else 1937 llvm::errs() << "NULL\n"; 1938 1939 llvm::errs() << " ---- to ----\n"; 1940 1941 if (const Stmt *s1End = getLocStmt(CP->getEndLocation())) 1942 s1End->dump(); 1943 else 1944 llvm::errs() << "NULL\n"; 1945 1946 break; 1947 } 1948 } 1949 1950 llvm::errs() << "\n"; 1951 } 1952} 1953 1954/// \brief Return true if X is contained by Y. 1955static bool lexicalContains(ParentMap &PM, 1956 const Stmt *X, 1957 const Stmt *Y) { 1958 while (X) { 1959 if (X == Y) 1960 return true; 1961 X = PM.getParent(X); 1962 } 1963 return false; 1964} 1965 1966// Remove short edges on the same line less than 3 columns in difference. 1967static void removePunyEdges(PathPieces &path, 1968 SourceManager &SM, 1969 ParentMap &PM) { 1970 1971 bool erased = false; 1972 1973 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; 1974 erased ? I : ++I) { 1975 1976 erased = false; 1977 1978 PathDiagnosticControlFlowPiece *PieceI = 1979 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 1980 1981 if (!PieceI) 1982 continue; 1983 1984 const Stmt *start = getLocStmt(PieceI->getStartLocation()); 1985 const Stmt *end = getLocStmt(PieceI->getEndLocation()); 1986 1987 if (!start || !end) 1988 continue; 1989 1990 const Stmt *endParent = PM.getParent(end); 1991 if (!endParent) 1992 continue; 1993 1994 if (isConditionForTerminator(end, endParent)) 1995 continue; 1996 1997 bool Invalid = false; 1998 FullSourceLoc StartL(start->getLocStart(), SM); 1999 FullSourceLoc EndL(end->getLocStart(), SM); 2000 2001 unsigned startLine = StartL.getSpellingLineNumber(&Invalid); 2002 if (Invalid) 2003 continue; 2004 2005 unsigned endLine = EndL.getSpellingLineNumber(&Invalid); 2006 if (Invalid) 2007 continue; 2008 2009 if (startLine != endLine) 2010 continue; 2011 2012 unsigned startCol = StartL.getSpellingColumnNumber(&Invalid); 2013 if (Invalid) 2014 continue; 2015 2016 unsigned endCol = EndL.getSpellingColumnNumber(&Invalid); 2017 if (Invalid) 2018 continue; 2019 2020 if (abs((int)startCol - (int)endCol) <= 2) { 2021 I = path.erase(I); 2022 erased = true; 2023 continue; 2024 } 2025 } 2026} 2027 2028static void removeIdenticalEvents(PathPieces &path) { 2029 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) { 2030 PathDiagnosticEventPiece *PieceI = 2031 dyn_cast<PathDiagnosticEventPiece>(*I); 2032 2033 if (!PieceI) 2034 continue; 2035 2036 PathPieces::iterator NextI = I; ++NextI; 2037 if (NextI == E) 2038 return; 2039 2040 PathDiagnosticEventPiece *PieceNextI = 2041 dyn_cast<PathDiagnosticEventPiece>(*NextI); 2042 2043 if (!PieceNextI) 2044 continue; 2045 2046 // Erase the second piece if it has the same exact message text. 2047 if (PieceI->getString() == PieceNextI->getString()) { 2048 path.erase(NextI); 2049 } 2050 } 2051} 2052 2053static bool optimizeEdges(PathPieces &path, SourceManager &SM, 2054 OptimizedCallsSet &OCS, 2055 LocationContextMap &LCM) { 2056 bool hasChanges = false; 2057 const LocationContext *LC = LCM[&path]; 2058 assert(LC); 2059 ParentMap &PM = LC->getParentMap(); 2060 bool isFirst = true; 2061 2062 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) { 2063 bool wasFirst = isFirst; 2064 isFirst = false; 2065 2066 // Optimize subpaths. 2067 if (PathDiagnosticCallPiece *CallI = dyn_cast<PathDiagnosticCallPiece>(*I)){ 2068 // Record the fact that a call has been optimized so we only do the 2069 // effort once. 2070 if (!OCS.count(CallI)) { 2071 while (optimizeEdges(CallI->path, SM, OCS, LCM)) {} 2072 OCS.insert(CallI); 2073 } 2074 ++I; 2075 continue; 2076 } 2077 2078 // Pattern match the current piece and its successor. 2079 PathDiagnosticControlFlowPiece *PieceI = 2080 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 2081 2082 if (!PieceI) { 2083 ++I; 2084 continue; 2085 } 2086 2087 const Stmt *s1Start = getLocStmt(PieceI->getStartLocation()); 2088 const Stmt *s1End = getLocStmt(PieceI->getEndLocation()); 2089 const Stmt *level1 = getStmtParent(s1Start, PM); 2090 const Stmt *level2 = getStmtParent(s1End, PM); 2091 2092 if (wasFirst) { 2093 // If the first edge (in isolation) is just a transition from 2094 // an expression to a parent expression then eliminate that edge. 2095 if (level1 && level2 && level2 == PM.getParent(level1)) { 2096 path.erase(I); 2097 // Since we are erasing the current edge at the start of the 2098 // path, just return now so we start analyzing the start of the path 2099 // again. 2100 return true; 2101 } 2102 2103 // If the first edge (in isolation) is a transition from the 2104 // initialization or increment in a for loop then remove it. 2105 if (level1 && isIncrementOrInitInForLoop(s1Start, level1)) { 2106 path.erase(I); 2107 return true; 2108 } 2109 } 2110 2111 PathPieces::iterator NextI = I; ++NextI; 2112 if (NextI == E) 2113 break; 2114 2115 PathDiagnosticControlFlowPiece *PieceNextI = 2116 dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 2117 2118 if (!PieceNextI) { 2119 ++I; 2120 continue; 2121 } 2122 2123 const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation()); 2124 const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation()); 2125 const Stmt *level3 = getStmtParent(s2Start, PM); 2126 const Stmt *level4 = getStmtParent(s2End, PM); 2127 2128 // Rule I. 2129 // 2130 // If we have two consecutive control edges whose end/begin locations 2131 // are at the same level (e.g. statements or top-level expressions within 2132 // a compound statement, or siblings share a single ancestor expression), 2133 // then merge them if they have no interesting intermediate event. 2134 // 2135 // For example: 2136 // 2137 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common 2138 // parent is '1'. Here 'x.y.z' represents the hierarchy of statements. 2139 // 2140 // NOTE: this will be limited later in cases where we add barriers 2141 // to prevent this optimization. 2142 // 2143 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) { 2144 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2145 path.erase(NextI); 2146 hasChanges = true; 2147 continue; 2148 } 2149 2150 // Rule II. 2151 // 2152 // Eliminate edges between subexpressions and parent expressions 2153 // when the subexpression is consumed. 2154 // 2155 // NOTE: this will be limited later in cases where we add barriers 2156 // to prevent this optimization. 2157 // 2158 if (s1End && s1End == s2Start && level2) { 2159 bool removeEdge = false; 2160 // Remove edges into the increment or initialization of a 2161 // loop that have no interleaving event. This means that 2162 // they aren't interesting. 2163 if (isIncrementOrInitInForLoop(s1End, level2)) 2164 removeEdge = true; 2165 // Next only consider edges that are not anchored on 2166 // the condition of a terminator. This are intermediate edges 2167 // that we might want to trim. 2168 else if (!isConditionForTerminator(level2, s1End)) { 2169 // Trim edges on expressions that are consumed by 2170 // the parent expression. 2171 if (isa<Expr>(s1End) && PM.isConsumedExpr(cast<Expr>(s1End))) { 2172 removeEdge = true; 2173 } 2174 // Trim edges where a lexical containment doesn't exist. 2175 // For example: 2176 // 2177 // X -> Y -> Z 2178 // 2179 // If 'Z' lexically contains Y (it is an ancestor) and 2180 // 'X' does not lexically contain Y (it is a descendant OR 2181 // it has no lexical relationship at all) then trim. 2182 // 2183 // This can eliminate edges where we dive into a subexpression 2184 // and then pop back out, etc. 2185 else if (s1Start && s2End && 2186 lexicalContains(PM, s2Start, s2End) && 2187 !lexicalContains(PM, s1End, s1Start)) { 2188 removeEdge = true; 2189 } 2190 } 2191 2192 if (removeEdge) { 2193 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2194 path.erase(NextI); 2195 hasChanges = true; 2196 continue; 2197 } 2198 } 2199 2200 // Optimize edges for ObjC fast-enumeration loops. 2201 // 2202 // (X -> collection) -> (collection -> element) 2203 // 2204 // becomes: 2205 // 2206 // (X -> element) 2207 if (s1End == s2Start) { 2208 const ObjCForCollectionStmt *FS = 2209 dyn_cast_or_null<ObjCForCollectionStmt>(level3); 2210 if (FS && FS->getCollection()->IgnoreParens() == s2Start && 2211 s2End == FS->getElement()) { 2212 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2213 path.erase(NextI); 2214 hasChanges = true; 2215 continue; 2216 } 2217 } 2218 2219 // No changes at this index? Move to the next one. 2220 ++I; 2221 } 2222 2223 if (!hasChanges) { 2224 // Remove any puny edges left over after primary optimization pass. 2225 removePunyEdges(path, SM, PM); 2226 // Remove identical events. 2227 removeIdenticalEvents(path); 2228 } 2229 2230 return hasChanges; 2231} 2232 2233/// \brief Split edges incident on a branch condition into two edges. 2234/// 2235/// The first edge is incident on the branch statement, the second on the 2236/// condition. 2237static void splitBranchConditionEdges(PathPieces &pieces, 2238 LocationContextMap &LCM, 2239 SourceManager &SM) { 2240 // Retrieve the parent map for this path. 2241 const LocationContext *LC = LCM[&pieces]; 2242 ParentMap &PM = LC->getParentMap(); 2243 PathPieces::iterator Prev = pieces.end(); 2244 for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; 2245 Prev = I, ++I) { 2246 // Adjust edges in subpaths. 2247 if (PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I)) { 2248 splitBranchConditionEdges(Call->path, LCM, SM); 2249 continue; 2250 } 2251 2252 PathDiagnosticControlFlowPiece *PieceI = 2253 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 2254 2255 if (!PieceI) 2256 continue; 2257 2258 // We are looking at two edges. Is the second one incident 2259 // on an expression (or subexpression) of a branch condition. 2260 const Stmt *Dst = getLocStmt(PieceI->getEndLocation()); 2261 const Stmt *Src = getLocStmt(PieceI->getStartLocation()); 2262 2263 if (!Dst || !Src) 2264 continue; 2265 2266 const Stmt *Branch = 0; 2267 const Stmt *S = Dst; 2268 while (const Stmt *Parent = getStmtParent(S, PM)) { 2269 if (const ForStmt *FS = dyn_cast<ForStmt>(Parent)) { 2270 const Stmt *Cond = FS->getCond(); 2271 if (!Cond) 2272 Cond = FS; 2273 if (Cond == S) 2274 Branch = FS; 2275 break; 2276 } 2277 if (const WhileStmt *WS = dyn_cast<WhileStmt>(Parent)) { 2278 if (WS->getCond()->IgnoreParens() == S) 2279 Branch = WS; 2280 break; 2281 } 2282 if (const IfStmt *IS = dyn_cast<IfStmt>(Parent)) { 2283 if (IS->getCond()->IgnoreParens() == S) 2284 Branch = IS; 2285 break; 2286 } 2287 if (const ObjCForCollectionStmt *OFS = 2288 dyn_cast<ObjCForCollectionStmt>(Parent)) { 2289 if (OFS->getElement() == S) 2290 Branch = OFS; 2291 break; 2292 } 2293 if (const BinaryOperator *BO = dyn_cast<BinaryOperator>(Parent)) { 2294 if (BO->isLogicalOp()) { 2295 if (BO->getLHS()->IgnoreParens() == S) 2296 Branch = BO; 2297 break; 2298 } 2299 } 2300 2301 S = Parent; 2302 } 2303 2304 // If 'Branch' is non-null we have found a match where we have an edge 2305 // incident on the condition of a if/for/while statement. 2306 if (!Branch) 2307 continue; 2308 2309 // If the current source of the edge is the if/for/while, then there is 2310 // nothing left to be done. 2311 if (Src == Branch) 2312 continue; 2313 2314 // Now look at the previous edge. We want to know if this was in the same 2315 // "level" as the for statement. 2316 const Stmt *BranchParent = getStmtParent(Branch, PM); 2317 PathDiagnosticLocation L(Branch, SM, LC); 2318 bool needsEdge = true; 2319 2320 if (Prev != E) { 2321 if (PathDiagnosticControlFlowPiece *P = 2322 dyn_cast<PathDiagnosticControlFlowPiece>(*Prev)) { 2323 const Stmt *PrevSrc = getLocStmt(P->getStartLocation()); 2324 if (PrevSrc) { 2325 const Stmt *PrevSrcParent = getStmtParent(PrevSrc, PM); 2326 if (PrevSrcParent == BranchParent) { 2327 P->setEndLocation(L); 2328 needsEdge = false; 2329 } 2330 } 2331 } 2332 } 2333 2334 if (needsEdge) { 2335 PathDiagnosticControlFlowPiece *P = 2336 new PathDiagnosticControlFlowPiece(PieceI->getStartLocation(), L); 2337 pieces.insert(I, P); 2338 } 2339 2340 PieceI->setStartLocation(L); 2341 } 2342} 2343 2344/// \brief Move edges from a branch condition to a branch target 2345/// when the condition is simple. 2346/// 2347/// This is the dual of splitBranchConditionEdges. That function creates 2348/// edges this may destroy, but they work together to create a more 2349/// aesthetically set of edges around branches. After the call to 2350/// splitBranchConditionEdges, we may have (1) an edge to the branch, 2351/// (2) an edge from the branch to the branch condition, and (3) an edge from 2352/// the branch condition to the branch target. We keep (1), but may wish 2353/// to remove (2) and move the source of (3) to the branch if the branch 2354/// condition is simple. 2355/// 2356static void simplifySimpleBranches(PathPieces &pieces) { 2357 2358 2359 for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; ++I) { 2360 // Adjust edges in subpaths. 2361 if (PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I)) { 2362 simplifySimpleBranches(Call->path); 2363 continue; 2364 } 2365 2366 PathDiagnosticControlFlowPiece *PieceI = 2367 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 2368 2369 if (!PieceI) 2370 continue; 2371 2372 const Stmt *s1Start = getLocStmt(PieceI->getStartLocation()); 2373 const Stmt *s1End = getLocStmt(PieceI->getEndLocation()); 2374 2375 if (!s1Start || !s1End) 2376 continue; 2377 2378 PathPieces::iterator NextI = I; ++NextI; 2379 if (NextI == E) 2380 break; 2381 2382 PathDiagnosticControlFlowPiece *PieceNextI = 0; 2383 2384 while (true) { 2385 if (NextI == E) 2386 break; 2387 2388 PathDiagnosticEventPiece *EV = dyn_cast<PathDiagnosticEventPiece>(*NextI); 2389 if (EV) { 2390 StringRef S = EV->getString(); 2391 if (S == StrEnteringLoop || S == StrLoopBodyZero) { 2392 ++NextI; 2393 continue; 2394 } 2395 break; 2396 } 2397 2398 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 2399 break; 2400 } 2401 2402 if (!PieceNextI) 2403 continue; 2404 2405 const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation()); 2406 const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation()); 2407 2408 if (!s2Start || !s2End || s1End != s2Start) 2409 continue; 2410 2411 // We only perform this transformation for specific branch kinds. 2412 // We do want to do this for do..while, for example. 2413 if (!(isa<ForStmt>(s1Start) || isa<WhileStmt>(s1Start) || 2414 isa<IfStmt>(s1Start) || isa<ObjCForCollectionStmt>(s1Start))) 2415 continue; 2416 2417 // Is s1End the branch condition? 2418 if (!isConditionForTerminator(s1Start, s1End)) 2419 continue; 2420 2421 // Perform the hoisting by eliminating (2) and changing the start 2422 // location of (3). 2423 PathDiagnosticLocation L = PieceI->getStartLocation(); 2424 pieces.erase(I); 2425 I = NextI; 2426 PieceNextI->setStartLocation(L); 2427 } 2428} 2429 2430//===----------------------------------------------------------------------===// 2431// Methods for BugType and subclasses. 2432//===----------------------------------------------------------------------===// 2433BugType::~BugType() { } 2434 2435void BugType::FlushReports(BugReporter &BR) {} 2436 2437void BuiltinBug::anchor() {} 2438 2439//===----------------------------------------------------------------------===// 2440// Methods for BugReport and subclasses. 2441//===----------------------------------------------------------------------===// 2442 2443void BugReport::NodeResolver::anchor() {} 2444 2445void BugReport::addVisitor(BugReporterVisitor* visitor) { 2446 if (!visitor) 2447 return; 2448 2449 llvm::FoldingSetNodeID ID; 2450 visitor->Profile(ID); 2451 void *InsertPos; 2452 2453 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) { 2454 delete visitor; 2455 return; 2456 } 2457 2458 CallbacksSet.InsertNode(visitor, InsertPos); 2459 Callbacks.push_back(visitor); 2460 ++ConfigurationChangeToken; 2461} 2462 2463BugReport::~BugReport() { 2464 for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) { 2465 delete *I; 2466 } 2467 while (!interestingSymbols.empty()) { 2468 popInterestingSymbolsAndRegions(); 2469 } 2470} 2471 2472const Decl *BugReport::getDeclWithIssue() const { 2473 if (DeclWithIssue) 2474 return DeclWithIssue; 2475 2476 const ExplodedNode *N = getErrorNode(); 2477 if (!N) 2478 return 0; 2479 2480 const LocationContext *LC = N->getLocationContext(); 2481 return LC->getCurrentStackFrame()->getDecl(); 2482} 2483 2484void BugReport::Profile(llvm::FoldingSetNodeID& hash) const { 2485 hash.AddPointer(&BT); 2486 hash.AddString(Description); 2487 PathDiagnosticLocation UL = getUniqueingLocation(); 2488 if (UL.isValid()) { 2489 UL.Profile(hash); 2490 } else if (Location.isValid()) { 2491 Location.Profile(hash); 2492 } else { 2493 assert(ErrorNode); 2494 hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode)); 2495 } 2496 2497 for (SmallVectorImpl<SourceRange>::const_iterator I = 2498 Ranges.begin(), E = Ranges.end(); I != E; ++I) { 2499 const SourceRange range = *I; 2500 if (!range.isValid()) 2501 continue; 2502 hash.AddInteger(range.getBegin().getRawEncoding()); 2503 hash.AddInteger(range.getEnd().getRawEncoding()); 2504 } 2505} 2506 2507void BugReport::markInteresting(SymbolRef sym) { 2508 if (!sym) 2509 return; 2510 2511 // If the symbol wasn't already in our set, note a configuration change. 2512 if (getInterestingSymbols().insert(sym).second) 2513 ++ConfigurationChangeToken; 2514 2515 if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym)) 2516 getInterestingRegions().insert(meta->getRegion()); 2517} 2518 2519void BugReport::markInteresting(const MemRegion *R) { 2520 if (!R) 2521 return; 2522 2523 // If the base region wasn't already in our set, note a configuration change. 2524 R = R->getBaseRegion(); 2525 if (getInterestingRegions().insert(R).second) 2526 ++ConfigurationChangeToken; 2527 2528 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2529 getInterestingSymbols().insert(SR->getSymbol()); 2530} 2531 2532void BugReport::markInteresting(SVal V) { 2533 markInteresting(V.getAsRegion()); 2534 markInteresting(V.getAsSymbol()); 2535} 2536 2537void BugReport::markInteresting(const LocationContext *LC) { 2538 if (!LC) 2539 return; 2540 InterestingLocationContexts.insert(LC); 2541} 2542 2543bool BugReport::isInteresting(SVal V) { 2544 return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol()); 2545} 2546 2547bool BugReport::isInteresting(SymbolRef sym) { 2548 if (!sym) 2549 return false; 2550 // We don't currently consider metadata symbols to be interesting 2551 // even if we know their region is interesting. Is that correct behavior? 2552 return getInterestingSymbols().count(sym); 2553} 2554 2555bool BugReport::isInteresting(const MemRegion *R) { 2556 if (!R) 2557 return false; 2558 R = R->getBaseRegion(); 2559 bool b = getInterestingRegions().count(R); 2560 if (b) 2561 return true; 2562 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2563 return getInterestingSymbols().count(SR->getSymbol()); 2564 return false; 2565} 2566 2567bool BugReport::isInteresting(const LocationContext *LC) { 2568 if (!LC) 2569 return false; 2570 return InterestingLocationContexts.count(LC); 2571} 2572 2573void BugReport::lazyInitializeInterestingSets() { 2574 if (interestingSymbols.empty()) { 2575 interestingSymbols.push_back(new Symbols()); 2576 interestingRegions.push_back(new Regions()); 2577 } 2578} 2579 2580BugReport::Symbols &BugReport::getInterestingSymbols() { 2581 lazyInitializeInterestingSets(); 2582 return *interestingSymbols.back(); 2583} 2584 2585BugReport::Regions &BugReport::getInterestingRegions() { 2586 lazyInitializeInterestingSets(); 2587 return *interestingRegions.back(); 2588} 2589 2590void BugReport::pushInterestingSymbolsAndRegions() { 2591 interestingSymbols.push_back(new Symbols(getInterestingSymbols())); 2592 interestingRegions.push_back(new Regions(getInterestingRegions())); 2593} 2594 2595void BugReport::popInterestingSymbolsAndRegions() { 2596 delete interestingSymbols.back(); 2597 interestingSymbols.pop_back(); 2598 delete interestingRegions.back(); 2599 interestingRegions.pop_back(); 2600} 2601 2602const Stmt *BugReport::getStmt() const { 2603 if (!ErrorNode) 2604 return 0; 2605 2606 ProgramPoint ProgP = ErrorNode->getLocation(); 2607 const Stmt *S = NULL; 2608 2609 if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) { 2610 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit(); 2611 if (BE->getBlock() == &Exit) 2612 S = GetPreviousStmt(ErrorNode); 2613 } 2614 if (!S) 2615 S = PathDiagnosticLocation::getStmt(ErrorNode); 2616 2617 return S; 2618} 2619 2620std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator> 2621BugReport::getRanges() { 2622 // If no custom ranges, add the range of the statement corresponding to 2623 // the error node. 2624 if (Ranges.empty()) { 2625 if (const Expr *E = dyn_cast_or_null<Expr>(getStmt())) 2626 addRange(E->getSourceRange()); 2627 else 2628 return std::make_pair(ranges_iterator(), ranges_iterator()); 2629 } 2630 2631 // User-specified absence of range info. 2632 if (Ranges.size() == 1 && !Ranges.begin()->isValid()) 2633 return std::make_pair(ranges_iterator(), ranges_iterator()); 2634 2635 return std::make_pair(Ranges.begin(), Ranges.end()); 2636} 2637 2638PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const { 2639 if (ErrorNode) { 2640 assert(!Location.isValid() && 2641 "Either Location or ErrorNode should be specified but not both."); 2642 return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM); 2643 } else { 2644 assert(Location.isValid()); 2645 return Location; 2646 } 2647 2648 return PathDiagnosticLocation(); 2649} 2650 2651//===----------------------------------------------------------------------===// 2652// Methods for BugReporter and subclasses. 2653//===----------------------------------------------------------------------===// 2654 2655BugReportEquivClass::~BugReportEquivClass() { } 2656GRBugReporter::~GRBugReporter() { } 2657BugReporterData::~BugReporterData() {} 2658 2659ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); } 2660 2661ProgramStateManager& 2662GRBugReporter::getStateManager() { return Eng.getStateManager(); } 2663 2664BugReporter::~BugReporter() { 2665 FlushReports(); 2666 2667 // Free the bug reports we are tracking. 2668 typedef std::vector<BugReportEquivClass *> ContTy; 2669 for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end(); 2670 I != E; ++I) { 2671 delete *I; 2672 } 2673} 2674 2675void BugReporter::FlushReports() { 2676 if (BugTypes.isEmpty()) 2677 return; 2678 2679 // First flush the warnings for each BugType. This may end up creating new 2680 // warnings and new BugTypes. 2681 // FIXME: Only NSErrorChecker needs BugType's FlushReports. 2682 // Turn NSErrorChecker into a proper checker and remove this. 2683 SmallVector<const BugType*, 16> bugTypes; 2684 for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I) 2685 bugTypes.push_back(*I); 2686 for (SmallVector<const BugType*, 16>::iterator 2687 I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I) 2688 const_cast<BugType*>(*I)->FlushReports(*this); 2689 2690 // We need to flush reports in deterministic order to ensure the order 2691 // of the reports is consistent between runs. 2692 typedef std::vector<BugReportEquivClass *> ContVecTy; 2693 for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.end(); 2694 EI != EE; ++EI){ 2695 BugReportEquivClass& EQ = **EI; 2696 FlushReport(EQ); 2697 } 2698 2699 // BugReporter owns and deletes only BugTypes created implicitly through 2700 // EmitBasicReport. 2701 // FIXME: There are leaks from checkers that assume that the BugTypes they 2702 // create will be destroyed by the BugReporter. 2703 for (llvm::StringMap<BugType*>::iterator 2704 I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I) 2705 delete I->second; 2706 2707 // Remove all references to the BugType objects. 2708 BugTypes = F.getEmptySet(); 2709} 2710 2711//===----------------------------------------------------------------------===// 2712// PathDiagnostics generation. 2713//===----------------------------------------------------------------------===// 2714 2715namespace { 2716/// A wrapper around a report graph, which contains only a single path, and its 2717/// node maps. 2718class ReportGraph { 2719public: 2720 InterExplodedGraphMap BackMap; 2721 OwningPtr<ExplodedGraph> Graph; 2722 const ExplodedNode *ErrorNode; 2723 size_t Index; 2724}; 2725 2726/// A wrapper around a trimmed graph and its node maps. 2727class TrimmedGraph { 2728 InterExplodedGraphMap InverseMap; 2729 2730 typedef llvm::DenseMap<const ExplodedNode *, unsigned> PriorityMapTy; 2731 PriorityMapTy PriorityMap; 2732 2733 typedef std::pair<const ExplodedNode *, size_t> NodeIndexPair; 2734 SmallVector<NodeIndexPair, 32> ReportNodes; 2735 2736 OwningPtr<ExplodedGraph> G; 2737 2738 /// A helper class for sorting ExplodedNodes by priority. 2739 template <bool Descending> 2740 class PriorityCompare { 2741 const PriorityMapTy &PriorityMap; 2742 2743 public: 2744 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {} 2745 2746 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const { 2747 PriorityMapTy::const_iterator LI = PriorityMap.find(LHS); 2748 PriorityMapTy::const_iterator RI = PriorityMap.find(RHS); 2749 PriorityMapTy::const_iterator E = PriorityMap.end(); 2750 2751 if (LI == E) 2752 return Descending; 2753 if (RI == E) 2754 return !Descending; 2755 2756 return Descending ? LI->second > RI->second 2757 : LI->second < RI->second; 2758 } 2759 2760 bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const { 2761 return (*this)(LHS.first, RHS.first); 2762 } 2763 }; 2764 2765public: 2766 TrimmedGraph(const ExplodedGraph *OriginalGraph, 2767 ArrayRef<const ExplodedNode *> Nodes); 2768 2769 bool popNextReportGraph(ReportGraph &GraphWrapper); 2770}; 2771} 2772 2773TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph, 2774 ArrayRef<const ExplodedNode *> Nodes) { 2775 // The trimmed graph is created in the body of the constructor to ensure 2776 // that the DenseMaps have been initialized already. 2777 InterExplodedGraphMap ForwardMap; 2778 G.reset(OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap)); 2779 2780 // Find the (first) error node in the trimmed graph. We just need to consult 2781 // the node map which maps from nodes in the original graph to nodes 2782 // in the new graph. 2783 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes; 2784 2785 for (unsigned i = 0, count = Nodes.size(); i < count; ++i) { 2786 if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) { 2787 ReportNodes.push_back(std::make_pair(NewNode, i)); 2788 RemainingNodes.insert(NewNode); 2789 } 2790 } 2791 2792 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph"); 2793 2794 // Perform a forward BFS to find all the shortest paths. 2795 std::queue<const ExplodedNode *> WS; 2796 2797 assert(G->num_roots() == 1); 2798 WS.push(*G->roots_begin()); 2799 unsigned Priority = 0; 2800 2801 while (!WS.empty()) { 2802 const ExplodedNode *Node = WS.front(); 2803 WS.pop(); 2804 2805 PriorityMapTy::iterator PriorityEntry; 2806 bool IsNew; 2807 llvm::tie(PriorityEntry, IsNew) = 2808 PriorityMap.insert(std::make_pair(Node, Priority)); 2809 ++Priority; 2810 2811 if (!IsNew) { 2812 assert(PriorityEntry->second <= Priority); 2813 continue; 2814 } 2815 2816 if (RemainingNodes.erase(Node)) 2817 if (RemainingNodes.empty()) 2818 break; 2819 2820 for (ExplodedNode::const_pred_iterator I = Node->succ_begin(), 2821 E = Node->succ_end(); 2822 I != E; ++I) 2823 WS.push(*I); 2824 } 2825 2826 // Sort the error paths from longest to shortest. 2827 std::sort(ReportNodes.begin(), ReportNodes.end(), 2828 PriorityCompare<true>(PriorityMap)); 2829} 2830 2831bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) { 2832 if (ReportNodes.empty()) 2833 return false; 2834 2835 const ExplodedNode *OrigN; 2836 llvm::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val(); 2837 assert(PriorityMap.find(OrigN) != PriorityMap.end() && 2838 "error node not accessible from root"); 2839 2840 // Create a new graph with a single path. This is the graph 2841 // that will be returned to the caller. 2842 ExplodedGraph *GNew = new ExplodedGraph(); 2843 GraphWrapper.Graph.reset(GNew); 2844 GraphWrapper.BackMap.clear(); 2845 2846 // Now walk from the error node up the BFS path, always taking the 2847 // predeccessor with the lowest number. 2848 ExplodedNode *Succ = 0; 2849 while (true) { 2850 // Create the equivalent node in the new graph with the same state 2851 // and location. 2852 ExplodedNode *NewN = GNew->getNode(OrigN->getLocation(), OrigN->getState(), 2853 OrigN->isSink()); 2854 2855 // Store the mapping to the original node. 2856 InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN); 2857 assert(IMitr != InverseMap.end() && "No mapping to original node."); 2858 GraphWrapper.BackMap[NewN] = IMitr->second; 2859 2860 // Link up the new node with the previous node. 2861 if (Succ) 2862 Succ->addPredecessor(NewN, *GNew); 2863 else 2864 GraphWrapper.ErrorNode = NewN; 2865 2866 Succ = NewN; 2867 2868 // Are we at the final node? 2869 if (OrigN->pred_empty()) { 2870 GNew->addRoot(NewN); 2871 break; 2872 } 2873 2874 // Find the next predeccessor node. We choose the node that is marked 2875 // with the lowest BFS number. 2876 OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(), 2877 PriorityCompare<false>(PriorityMap)); 2878 } 2879 2880 return true; 2881} 2882 2883 2884/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object 2885/// and collapses PathDiagosticPieces that are expanded by macros. 2886static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) { 2887 typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>, 2888 SourceLocation> > MacroStackTy; 2889 2890 typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> > 2891 PiecesTy; 2892 2893 MacroStackTy MacroStack; 2894 PiecesTy Pieces; 2895 2896 for (PathPieces::const_iterator I = path.begin(), E = path.end(); 2897 I!=E; ++I) { 2898 2899 PathDiagnosticPiece *piece = I->getPtr(); 2900 2901 // Recursively compact calls. 2902 if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){ 2903 CompactPathDiagnostic(call->path, SM); 2904 } 2905 2906 // Get the location of the PathDiagnosticPiece. 2907 const FullSourceLoc Loc = piece->getLocation().asLocation(); 2908 2909 // Determine the instantiation location, which is the location we group 2910 // related PathDiagnosticPieces. 2911 SourceLocation InstantiationLoc = Loc.isMacroID() ? 2912 SM.getExpansionLoc(Loc) : 2913 SourceLocation(); 2914 2915 if (Loc.isFileID()) { 2916 MacroStack.clear(); 2917 Pieces.push_back(piece); 2918 continue; 2919 } 2920 2921 assert(Loc.isMacroID()); 2922 2923 // Is the PathDiagnosticPiece within the same macro group? 2924 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) { 2925 MacroStack.back().first->subPieces.push_back(piece); 2926 continue; 2927 } 2928 2929 // We aren't in the same group. Are we descending into a new macro 2930 // or are part of an old one? 2931 IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup; 2932 2933 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ? 2934 SM.getExpansionLoc(Loc) : 2935 SourceLocation(); 2936 2937 // Walk the entire macro stack. 2938 while (!MacroStack.empty()) { 2939 if (InstantiationLoc == MacroStack.back().second) { 2940 MacroGroup = MacroStack.back().first; 2941 break; 2942 } 2943 2944 if (ParentInstantiationLoc == MacroStack.back().second) { 2945 MacroGroup = MacroStack.back().first; 2946 break; 2947 } 2948 2949 MacroStack.pop_back(); 2950 } 2951 2952 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) { 2953 // Create a new macro group and add it to the stack. 2954 PathDiagnosticMacroPiece *NewGroup = 2955 new PathDiagnosticMacroPiece( 2956 PathDiagnosticLocation::createSingleLocation(piece->getLocation())); 2957 2958 if (MacroGroup) 2959 MacroGroup->subPieces.push_back(NewGroup); 2960 else { 2961 assert(InstantiationLoc.isFileID()); 2962 Pieces.push_back(NewGroup); 2963 } 2964 2965 MacroGroup = NewGroup; 2966 MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc)); 2967 } 2968 2969 // Finally, add the PathDiagnosticPiece to the group. 2970 MacroGroup->subPieces.push_back(piece); 2971 } 2972 2973 // Now take the pieces and construct a new PathDiagnostic. 2974 path.clear(); 2975 2976 for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I) 2977 path.push_back(*I); 2978} 2979 2980bool GRBugReporter::generatePathDiagnostic(PathDiagnostic& PD, 2981 PathDiagnosticConsumer &PC, 2982 ArrayRef<BugReport *> &bugReports) { 2983 assert(!bugReports.empty()); 2984 2985 bool HasValid = false; 2986 bool HasInvalid = false; 2987 SmallVector<const ExplodedNode *, 32> errorNodes; 2988 for (ArrayRef<BugReport*>::iterator I = bugReports.begin(), 2989 E = bugReports.end(); I != E; ++I) { 2990 if ((*I)->isValid()) { 2991 HasValid = true; 2992 errorNodes.push_back((*I)->getErrorNode()); 2993 } else { 2994 // Keep the errorNodes list in sync with the bugReports list. 2995 HasInvalid = true; 2996 errorNodes.push_back(0); 2997 } 2998 } 2999 3000 // If all the reports have been marked invalid by a previous path generation, 3001 // we're done. 3002 if (!HasValid) 3003 return false; 3004 3005 typedef PathDiagnosticConsumer::PathGenerationScheme PathGenerationScheme; 3006 PathGenerationScheme ActiveScheme = PC.getGenerationScheme(); 3007 3008 if (ActiveScheme == PathDiagnosticConsumer::Extensive) { 3009 AnalyzerOptions &options = getAnalyzerOptions(); 3010 if (options.getBooleanOption("path-diagnostics-alternate", false)) { 3011 ActiveScheme = PathDiagnosticConsumer::AlternateExtensive; 3012 } 3013 } 3014 3015 TrimmedGraph TrimG(&getGraph(), errorNodes); 3016 ReportGraph ErrorGraph; 3017 3018 while (TrimG.popNextReportGraph(ErrorGraph)) { 3019 // Find the BugReport with the original location. 3020 assert(ErrorGraph.Index < bugReports.size()); 3021 BugReport *R = bugReports[ErrorGraph.Index]; 3022 assert(R && "No original report found for sliced graph."); 3023 assert(R->isValid() && "Report selected by trimmed graph marked invalid."); 3024 3025 // Start building the path diagnostic... 3026 PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, &PC); 3027 const ExplodedNode *N = ErrorGraph.ErrorNode; 3028 3029 // Register additional node visitors. 3030 R->addVisitor(new NilReceiverBRVisitor()); 3031 R->addVisitor(new ConditionBRVisitor()); 3032 R->addVisitor(new LikelyFalsePositiveSuppressionBRVisitor()); 3033 3034 BugReport::VisitorList visitors; 3035 unsigned origReportConfigToken, finalReportConfigToken; 3036 LocationContextMap LCM; 3037 3038 // While generating diagnostics, it's possible the visitors will decide 3039 // new symbols and regions are interesting, or add other visitors based on 3040 // the information they find. If they do, we need to regenerate the path 3041 // based on our new report configuration. 3042 do { 3043 // Get a clean copy of all the visitors. 3044 for (BugReport::visitor_iterator I = R->visitor_begin(), 3045 E = R->visitor_end(); I != E; ++I) 3046 visitors.push_back((*I)->clone()); 3047 3048 // Clear out the active path from any previous work. 3049 PD.resetPath(); 3050 origReportConfigToken = R->getConfigurationChangeToken(); 3051 3052 // Generate the very last diagnostic piece - the piece is visible before 3053 // the trace is expanded. 3054 PathDiagnosticPiece *LastPiece = 0; 3055 for (BugReport::visitor_iterator I = visitors.begin(), E = visitors.end(); 3056 I != E; ++I) { 3057 if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) { 3058 assert (!LastPiece && 3059 "There can only be one final piece in a diagnostic."); 3060 LastPiece = Piece; 3061 } 3062 } 3063 3064 if (ActiveScheme != PathDiagnosticConsumer::None) { 3065 if (!LastPiece) 3066 LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R); 3067 assert(LastPiece); 3068 PD.setEndOfPath(LastPiece); 3069 } 3070 3071 // Make sure we get a clean location context map so we don't 3072 // hold onto old mappings. 3073 LCM.clear(); 3074 3075 switch (ActiveScheme) { 3076 case PathDiagnosticConsumer::AlternateExtensive: 3077 GenerateAlternateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 3078 break; 3079 case PathDiagnosticConsumer::Extensive: 3080 GenerateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 3081 break; 3082 case PathDiagnosticConsumer::Minimal: 3083 GenerateMinimalPathDiagnostic(PD, PDB, N, LCM, visitors); 3084 break; 3085 case PathDiagnosticConsumer::None: 3086 GenerateVisitorsOnlyPathDiagnostic(PD, PDB, N, visitors); 3087 break; 3088 } 3089 3090 // Clean up the visitors we used. 3091 llvm::DeleteContainerPointers(visitors); 3092 3093 // Did anything change while generating this path? 3094 finalReportConfigToken = R->getConfigurationChangeToken(); 3095 } while (finalReportConfigToken != origReportConfigToken); 3096 3097 if (!R->isValid()) 3098 continue; 3099 3100 // Finally, prune the diagnostic path of uninteresting stuff. 3101 if (!PD.path.empty()) { 3102 // Remove messages that are basically the same. 3103 removeRedundantMsgs(PD.getMutablePieces()); 3104 3105 if (R->shouldPrunePath() && getAnalyzerOptions().shouldPrunePaths()) { 3106 bool stillHasNotes = removeUnneededCalls(PD.getMutablePieces(), R, LCM); 3107 assert(stillHasNotes); 3108 (void)stillHasNotes; 3109 } 3110 3111 adjustCallLocations(PD.getMutablePieces()); 3112 3113 if (ActiveScheme == PathDiagnosticConsumer::AlternateExtensive) { 3114 SourceManager &SM = getSourceManager(); 3115 3116 // Reduce the number of edges from a very conservative set 3117 // to an aesthetically pleasing subset that conveys the 3118 // necessary information. 3119 OptimizedCallsSet OCS; 3120 while (optimizeEdges(PD.getMutablePieces(), SM, OCS, LCM)) {} 3121 3122 // Adjust edges into loop conditions to make them more uniform 3123 // and aesthetically pleasing. 3124 splitBranchConditionEdges(PD.getMutablePieces(), LCM, SM); 3125 3126 // Hoist edges originating from branch conditions to branches 3127 // for simple branches. 3128 simplifySimpleBranches(PD.getMutablePieces()); 3129 } 3130 } 3131 3132 // We found a report and didn't suppress it. 3133 return true; 3134 } 3135 3136 // We suppressed all the reports in this equivalence class. 3137 assert(!HasInvalid && "Inconsistent suppression"); 3138 (void)HasInvalid; 3139 return false; 3140} 3141 3142void BugReporter::Register(BugType *BT) { 3143 BugTypes = F.add(BugTypes, BT); 3144} 3145 3146void BugReporter::emitReport(BugReport* R) { 3147 // Compute the bug report's hash to determine its equivalence class. 3148 llvm::FoldingSetNodeID ID; 3149 R->Profile(ID); 3150 3151 // Lookup the equivance class. If there isn't one, create it. 3152 BugType& BT = R->getBugType(); 3153 Register(&BT); 3154 void *InsertPos; 3155 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos); 3156 3157 if (!EQ) { 3158 EQ = new BugReportEquivClass(R); 3159 EQClasses.InsertNode(EQ, InsertPos); 3160 EQClassesVector.push_back(EQ); 3161 } 3162 else 3163 EQ->AddReport(R); 3164} 3165 3166 3167//===----------------------------------------------------------------------===// 3168// Emitting reports in equivalence classes. 3169//===----------------------------------------------------------------------===// 3170 3171namespace { 3172struct FRIEC_WLItem { 3173 const ExplodedNode *N; 3174 ExplodedNode::const_succ_iterator I, E; 3175 3176 FRIEC_WLItem(const ExplodedNode *n) 3177 : N(n), I(N->succ_begin()), E(N->succ_end()) {} 3178}; 3179} 3180 3181static BugReport * 3182FindReportInEquivalenceClass(BugReportEquivClass& EQ, 3183 SmallVectorImpl<BugReport*> &bugReports) { 3184 3185 BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end(); 3186 assert(I != E); 3187 BugType& BT = I->getBugType(); 3188 3189 // If we don't need to suppress any of the nodes because they are 3190 // post-dominated by a sink, simply add all the nodes in the equivalence class 3191 // to 'Nodes'. Any of the reports will serve as a "representative" report. 3192 if (!BT.isSuppressOnSink()) { 3193 BugReport *R = I; 3194 for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) { 3195 const ExplodedNode *N = I->getErrorNode(); 3196 if (N) { 3197 R = I; 3198 bugReports.push_back(R); 3199 } 3200 } 3201 return R; 3202 } 3203 3204 // For bug reports that should be suppressed when all paths are post-dominated 3205 // by a sink node, iterate through the reports in the equivalence class 3206 // until we find one that isn't post-dominated (if one exists). We use a 3207 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write 3208 // this as a recursive function, but we don't want to risk blowing out the 3209 // stack for very long paths. 3210 BugReport *exampleReport = 0; 3211 3212 for (; I != E; ++I) { 3213 const ExplodedNode *errorNode = I->getErrorNode(); 3214 3215 if (!errorNode) 3216 continue; 3217 if (errorNode->isSink()) { 3218 llvm_unreachable( 3219 "BugType::isSuppressSink() should not be 'true' for sink end nodes"); 3220 } 3221 // No successors? By definition this nodes isn't post-dominated by a sink. 3222 if (errorNode->succ_empty()) { 3223 bugReports.push_back(I); 3224 if (!exampleReport) 3225 exampleReport = I; 3226 continue; 3227 } 3228 3229 // At this point we know that 'N' is not a sink and it has at least one 3230 // successor. Use a DFS worklist to find a non-sink end-of-path node. 3231 typedef FRIEC_WLItem WLItem; 3232 typedef SmallVector<WLItem, 10> DFSWorkList; 3233 llvm::DenseMap<const ExplodedNode *, unsigned> Visited; 3234 3235 DFSWorkList WL; 3236 WL.push_back(errorNode); 3237 Visited[errorNode] = 1; 3238 3239 while (!WL.empty()) { 3240 WLItem &WI = WL.back(); 3241 assert(!WI.N->succ_empty()); 3242 3243 for (; WI.I != WI.E; ++WI.I) { 3244 const ExplodedNode *Succ = *WI.I; 3245 // End-of-path node? 3246 if (Succ->succ_empty()) { 3247 // If we found an end-of-path node that is not a sink. 3248 if (!Succ->isSink()) { 3249 bugReports.push_back(I); 3250 if (!exampleReport) 3251 exampleReport = I; 3252 WL.clear(); 3253 break; 3254 } 3255 // Found a sink? Continue on to the next successor. 3256 continue; 3257 } 3258 // Mark the successor as visited. If it hasn't been explored, 3259 // enqueue it to the DFS worklist. 3260 unsigned &mark = Visited[Succ]; 3261 if (!mark) { 3262 mark = 1; 3263 WL.push_back(Succ); 3264 break; 3265 } 3266 } 3267 3268 // The worklist may have been cleared at this point. First 3269 // check if it is empty before checking the last item. 3270 if (!WL.empty() && &WL.back() == &WI) 3271 WL.pop_back(); 3272 } 3273 } 3274 3275 // ExampleReport will be NULL if all the nodes in the equivalence class 3276 // were post-dominated by sinks. 3277 return exampleReport; 3278} 3279 3280void BugReporter::FlushReport(BugReportEquivClass& EQ) { 3281 SmallVector<BugReport*, 10> bugReports; 3282 BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports); 3283 if (exampleReport) { 3284 const PathDiagnosticConsumers &C = getPathDiagnosticConsumers(); 3285 for (PathDiagnosticConsumers::const_iterator I=C.begin(), 3286 E=C.end(); I != E; ++I) { 3287 FlushReport(exampleReport, **I, bugReports); 3288 } 3289 } 3290} 3291 3292void BugReporter::FlushReport(BugReport *exampleReport, 3293 PathDiagnosticConsumer &PD, 3294 ArrayRef<BugReport*> bugReports) { 3295 3296 // FIXME: Make sure we use the 'R' for the path that was actually used. 3297 // Probably doesn't make a difference in practice. 3298 BugType& BT = exampleReport->getBugType(); 3299 3300 OwningPtr<PathDiagnostic> 3301 D(new PathDiagnostic(exampleReport->getDeclWithIssue(), 3302 exampleReport->getBugType().getName(), 3303 exampleReport->getDescription(), 3304 exampleReport->getShortDescription(/*Fallback=*/false), 3305 BT.getCategory(), 3306 exampleReport->getUniqueingLocation(), 3307 exampleReport->getUniqueingDecl())); 3308 3309 MaxBugClassSize = std::max(bugReports.size(), 3310 static_cast<size_t>(MaxBugClassSize)); 3311 3312 // Generate the full path diagnostic, using the generation scheme 3313 // specified by the PathDiagnosticConsumer. Note that we have to generate 3314 // path diagnostics even for consumers which do not support paths, because 3315 // the BugReporterVisitors may mark this bug as a false positive. 3316 if (!bugReports.empty()) 3317 if (!generatePathDiagnostic(*D.get(), PD, bugReports)) 3318 return; 3319 3320 MaxValidBugClassSize = std::max(bugReports.size(), 3321 static_cast<size_t>(MaxValidBugClassSize)); 3322 3323 // Examine the report and see if the last piece is in a header. Reset the 3324 // report location to the last piece in the main source file. 3325 AnalyzerOptions& Opts = getAnalyzerOptions(); 3326 if (Opts.shouldReportIssuesInMainSourceFile() && !Opts.AnalyzeAll) 3327 D->resetDiagnosticLocationToMainFile(); 3328 3329 // If the path is empty, generate a single step path with the location 3330 // of the issue. 3331 if (D->path.empty()) { 3332 PathDiagnosticLocation L = exampleReport->getLocation(getSourceManager()); 3333 PathDiagnosticPiece *piece = 3334 new PathDiagnosticEventPiece(L, exampleReport->getDescription()); 3335 BugReport::ranges_iterator Beg, End; 3336 llvm::tie(Beg, End) = exampleReport->getRanges(); 3337 for ( ; Beg != End; ++Beg) 3338 piece->addRange(*Beg); 3339 D->setEndOfPath(piece); 3340 } 3341 3342 // Get the meta data. 3343 const BugReport::ExtraTextList &Meta = exampleReport->getExtraText(); 3344 for (BugReport::ExtraTextList::const_iterator i = Meta.begin(), 3345 e = Meta.end(); i != e; ++i) { 3346 D->addMeta(*i); 3347 } 3348 3349 PD.HandlePathDiagnostic(D.take()); 3350} 3351 3352void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, 3353 StringRef name, 3354 StringRef category, 3355 StringRef str, PathDiagnosticLocation Loc, 3356 SourceRange* RBeg, unsigned NumRanges) { 3357 3358 // 'BT' is owned by BugReporter. 3359 BugType *BT = getBugTypeForName(name, category); 3360 BugReport *R = new BugReport(*BT, str, Loc); 3361 R->setDeclWithIssue(DeclWithIssue); 3362 for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg); 3363 emitReport(R); 3364} 3365 3366BugType *BugReporter::getBugTypeForName(StringRef name, 3367 StringRef category) { 3368 SmallString<136> fullDesc; 3369 llvm::raw_svector_ostream(fullDesc) << name << ":" << category; 3370 llvm::StringMapEntry<BugType *> & 3371 entry = StrBugTypes.GetOrCreateValue(fullDesc); 3372 BugType *BT = entry.getValue(); 3373 if (!BT) { 3374 BT = new BugType(name, category); 3375 entry.setValue(BT); 3376 } 3377 return BT; 3378} 3379