BugReporter.cpp revision 1dfebd9f995066a229c34516eb14bc69c6bcde2c
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#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 16#include "clang/AST/ASTContext.h" 17#include "clang/AST/DeclObjC.h" 18#include "clang/AST/Expr.h" 19#include "clang/AST/ParentMap.h" 20#include "clang/AST/StmtObjC.h" 21#include "clang/Analysis/CFG.h" 22#include "clang/Analysis/ProgramPoint.h" 23#include "clang/Basic/SourceManager.h" 24#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 25#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h" 26#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 27#include "llvm/ADT/DenseMap.h" 28#include "llvm/ADT/IntrusiveRefCntPtr.h" 29#include "llvm/ADT/OwningPtr.h" 30#include "llvm/ADT/STLExtras.h" 31#include "llvm/ADT/SmallString.h" 32#include "llvm/Support/raw_ostream.h" 33#include <queue> 34 35using namespace clang; 36using namespace ento; 37 38BugReporterVisitor::~BugReporterVisitor() {} 39 40void BugReporterContext::anchor() {} 41 42//===----------------------------------------------------------------------===// 43// Helper routines for walking the ExplodedGraph and fetching statements. 44//===----------------------------------------------------------------------===// 45 46static inline const Stmt *GetStmt(const ProgramPoint &P) { 47 if (const StmtPoint* SP = dyn_cast<StmtPoint>(&P)) 48 return SP->getStmt(); 49 else if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) 50 return BE->getSrc()->getTerminator(); 51 else if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) 52 return CE->getCallExpr(); 53 else if (const CallExitEnd *CEE = dyn_cast<CallExitEnd>(&P)) 54 return CEE->getCalleeContext()->getCallSite(); 55 56 return 0; 57} 58 59static inline const ExplodedNode* 60GetPredecessorNode(const ExplodedNode *N) { 61 return N->pred_empty() ? NULL : *(N->pred_begin()); 62} 63 64static inline const ExplodedNode* 65GetSuccessorNode(const ExplodedNode *N) { 66 return N->succ_empty() ? NULL : *(N->succ_begin()); 67} 68 69static const Stmt *GetPreviousStmt(const ExplodedNode *N) { 70 for (N = GetPredecessorNode(N); N; N = GetPredecessorNode(N)) 71 if (const Stmt *S = GetStmt(N->getLocation())) 72 return S; 73 74 return 0; 75} 76 77static const Stmt *GetNextStmt(const ExplodedNode *N) { 78 for (N = GetSuccessorNode(N); N; N = GetSuccessorNode(N)) 79 if (const Stmt *S = GetStmt(N->getLocation())) { 80 // Check if the statement is '?' or '&&'/'||'. These are "merges", 81 // not actual statement points. 82 switch (S->getStmtClass()) { 83 case Stmt::ChooseExprClass: 84 case Stmt::BinaryConditionalOperatorClass: continue; 85 case Stmt::ConditionalOperatorClass: continue; 86 case Stmt::BinaryOperatorClass: { 87 BinaryOperatorKind Op = cast<BinaryOperator>(S)->getOpcode(); 88 if (Op == BO_LAnd || Op == BO_LOr) 89 continue; 90 break; 91 } 92 default: 93 break; 94 } 95 return S; 96 } 97 98 return 0; 99} 100 101static inline const Stmt* 102GetCurrentOrPreviousStmt(const ExplodedNode *N) { 103 if (const Stmt *S = GetStmt(N->getLocation())) 104 return S; 105 106 return GetPreviousStmt(N); 107} 108 109static inline const Stmt* 110GetCurrentOrNextStmt(const ExplodedNode *N) { 111 if (const Stmt *S = GetStmt(N->getLocation())) 112 return S; 113 114 return GetNextStmt(N); 115} 116 117//===----------------------------------------------------------------------===// 118// Diagnostic cleanup. 119//===----------------------------------------------------------------------===// 120 121static PathDiagnosticEventPiece * 122eventsDescribeSameCondition(PathDiagnosticEventPiece *X, 123 PathDiagnosticEventPiece *Y) { 124 // Prefer diagnostics that come from ConditionBRVisitor over 125 // those that came from TrackConstraintBRVisitor. 126 const void *tagPreferred = ConditionBRVisitor::getTag(); 127 const void *tagLesser = TrackConstraintBRVisitor::getTag(); 128 129 if (X->getLocation() != Y->getLocation()) 130 return 0; 131 132 if (X->getTag() == tagPreferred && Y->getTag() == tagLesser) 133 return X; 134 135 if (Y->getTag() == tagPreferred && X->getTag() == tagLesser) 136 return Y; 137 138 return 0; 139} 140 141/// An optimization pass over PathPieces that removes redundant diagnostics 142/// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both 143/// BugReporterVisitors use different methods to generate diagnostics, with 144/// one capable of emitting diagnostics in some cases but not in others. This 145/// can lead to redundant diagnostic pieces at the same point in a path. 146static void removeRedundantMsgs(PathPieces &path) { 147 unsigned N = path.size(); 148 if (N < 2) 149 return; 150 // NOTE: this loop intentionally is not using an iterator. Instead, we 151 // are streaming the path and modifying it in place. This is done by 152 // grabbing the front, processing it, and if we decide to keep it append 153 // it to the end of the path. The entire path is processed in this way. 154 for (unsigned i = 0; i < N; ++i) { 155 IntrusiveRefCntPtr<PathDiagnosticPiece> piece(path.front()); 156 path.pop_front(); 157 158 switch (piece->getKind()) { 159 case clang::ento::PathDiagnosticPiece::Call: 160 removeRedundantMsgs(cast<PathDiagnosticCallPiece>(piece)->path); 161 break; 162 case clang::ento::PathDiagnosticPiece::Macro: 163 removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(piece)->subPieces); 164 break; 165 case clang::ento::PathDiagnosticPiece::ControlFlow: 166 break; 167 case clang::ento::PathDiagnosticPiece::Event: { 168 if (i == N-1) 169 break; 170 171 if (PathDiagnosticEventPiece *nextEvent = 172 dyn_cast<PathDiagnosticEventPiece>(path.front().getPtr())) { 173 PathDiagnosticEventPiece *event = 174 cast<PathDiagnosticEventPiece>(piece); 175 // Check to see if we should keep one of the two pieces. If we 176 // come up with a preference, record which piece to keep, and consume 177 // another piece from the path. 178 if (PathDiagnosticEventPiece *pieceToKeep = 179 eventsDescribeSameCondition(event, nextEvent)) { 180 piece = pieceToKeep; 181 path.pop_front(); 182 ++i; 183 } 184 } 185 break; 186 } 187 } 188 path.push_back(piece); 189 } 190} 191 192/// Recursively scan through a path and prune out calls and macros pieces 193/// that aren't needed. Return true if afterwards the path contains 194/// "interesting stuff" which means it shouldn't be pruned from the parent path. 195bool BugReporter::RemoveUnneededCalls(PathPieces &pieces, BugReport *R) { 196 bool containsSomethingInteresting = false; 197 const unsigned N = pieces.size(); 198 199 for (unsigned i = 0 ; i < N ; ++i) { 200 // Remove the front piece from the path. If it is still something we 201 // want to keep once we are done, we will push it back on the end. 202 IntrusiveRefCntPtr<PathDiagnosticPiece> piece(pieces.front()); 203 pieces.pop_front(); 204 205 // Throw away pieces with invalid locations. Note that we can't throw away 206 // calls just yet because they might have something interesting inside them. 207 // If so, their locations will be adjusted as necessary later. 208 if (piece->getKind() != PathDiagnosticPiece::Call && 209 piece->getLocation().asLocation().isInvalid()) 210 continue; 211 212 switch (piece->getKind()) { 213 case PathDiagnosticPiece::Call: { 214 PathDiagnosticCallPiece *call = cast<PathDiagnosticCallPiece>(piece); 215 // Check if the location context is interesting. 216 assert(LocationContextMap.count(call)); 217 if (R->isInteresting(LocationContextMap[call])) { 218 containsSomethingInteresting = true; 219 break; 220 } 221 222 if (!RemoveUnneededCalls(call->path, R)) 223 continue; 224 225 containsSomethingInteresting = true; 226 break; 227 } 228 case PathDiagnosticPiece::Macro: { 229 PathDiagnosticMacroPiece *macro = cast<PathDiagnosticMacroPiece>(piece); 230 if (!RemoveUnneededCalls(macro->subPieces, R)) 231 continue; 232 containsSomethingInteresting = true; 233 break; 234 } 235 case PathDiagnosticPiece::Event: { 236 PathDiagnosticEventPiece *event = cast<PathDiagnosticEventPiece>(piece); 237 238 // We never throw away an event, but we do throw it away wholesale 239 // as part of a path if we throw the entire path away. 240 containsSomethingInteresting |= !event->isPrunable(); 241 break; 242 } 243 case PathDiagnosticPiece::ControlFlow: 244 break; 245 } 246 247 pieces.push_back(piece); 248 } 249 250 return containsSomethingInteresting; 251} 252 253/// Recursively scan through a path and make sure that all call pieces have 254/// valid locations. Note that all other pieces with invalid locations should 255/// have already been pruned out. 256static void adjustCallLocations(PathPieces &Pieces, 257 PathDiagnosticLocation *LastCallLocation = 0) { 258 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E; ++I) { 259 PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I); 260 261 if (!Call) { 262 assert((*I)->getLocation().asLocation().isValid()); 263 continue; 264 } 265 266 if (LastCallLocation) { 267 if (!Call->callEnter.asLocation().isValid()) 268 Call->callEnter = *LastCallLocation; 269 if (!Call->callReturn.asLocation().isValid()) 270 Call->callReturn = *LastCallLocation; 271 } 272 273 // Recursively clean out the subclass. Keep this call around if 274 // it contains any informative diagnostics. 275 PathDiagnosticLocation *ThisCallLocation; 276 if (Call->callEnterWithin.asLocation().isValid()) 277 ThisCallLocation = &Call->callEnterWithin; 278 else 279 ThisCallLocation = &Call->callEnter; 280 281 assert(ThisCallLocation && "Outermost call has an invalid location"); 282 adjustCallLocations(Call->path, ThisCallLocation); 283 } 284} 285 286//===----------------------------------------------------------------------===// 287// PathDiagnosticBuilder and its associated routines and helper objects. 288//===----------------------------------------------------------------------===// 289 290typedef llvm::DenseMap<const ExplodedNode*, 291const ExplodedNode*> NodeBackMap; 292 293namespace { 294class NodeMapClosure : public BugReport::NodeResolver { 295 NodeBackMap& M; 296public: 297 NodeMapClosure(NodeBackMap *m) : M(*m) {} 298 ~NodeMapClosure() {} 299 300 const ExplodedNode *getOriginalNode(const ExplodedNode *N) { 301 NodeBackMap::iterator I = M.find(N); 302 return I == M.end() ? 0 : I->second; 303 } 304}; 305 306class PathDiagnosticBuilder : public BugReporterContext { 307 BugReport *R; 308 PathDiagnosticConsumer *PDC; 309 OwningPtr<ParentMap> PM; 310 NodeMapClosure NMC; 311public: 312 const LocationContext *LC; 313 314 PathDiagnosticBuilder(GRBugReporter &br, 315 BugReport *r, NodeBackMap *Backmap, 316 PathDiagnosticConsumer *pdc) 317 : BugReporterContext(br), 318 R(r), PDC(pdc), NMC(Backmap), LC(r->getErrorNode()->getLocationContext()) 319 {} 320 321 PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N); 322 323 PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os, 324 const ExplodedNode *N); 325 326 BugReport *getBugReport() { return R; } 327 328 Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); } 329 330 ParentMap& getParentMap() { return LC->getParentMap(); } 331 332 const Stmt *getParent(const Stmt *S) { 333 return getParentMap().getParent(S); 334 } 335 336 virtual NodeMapClosure& getNodeResolver() { return NMC; } 337 338 PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S); 339 340 PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const { 341 return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Extensive; 342 } 343 344 bool supportsLogicalOpControlFlow() const { 345 return PDC ? PDC->supportsLogicalOpControlFlow() : true; 346 } 347}; 348} // end anonymous namespace 349 350PathDiagnosticLocation 351PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) { 352 if (const Stmt *S = GetNextStmt(N)) 353 return PathDiagnosticLocation(S, getSourceManager(), LC); 354 355 return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(), 356 getSourceManager()); 357} 358 359PathDiagnosticLocation 360PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os, 361 const ExplodedNode *N) { 362 363 // Slow, but probably doesn't matter. 364 if (os.str().empty()) 365 os << ' '; 366 367 const PathDiagnosticLocation &Loc = ExecutionContinues(N); 368 369 if (Loc.asStmt()) 370 os << "Execution continues on line " 371 << getSourceManager().getExpansionLineNumber(Loc.asLocation()) 372 << '.'; 373 else { 374 os << "Execution jumps to the end of the "; 375 const Decl *D = N->getLocationContext()->getDecl(); 376 if (isa<ObjCMethodDecl>(D)) 377 os << "method"; 378 else if (isa<FunctionDecl>(D)) 379 os << "function"; 380 else { 381 assert(isa<BlockDecl>(D)); 382 os << "anonymous block"; 383 } 384 os << '.'; 385 } 386 387 return Loc; 388} 389 390static bool IsNested(const Stmt *S, ParentMap &PM) { 391 if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S))) 392 return true; 393 394 const Stmt *Parent = PM.getParentIgnoreParens(S); 395 396 if (Parent) 397 switch (Parent->getStmtClass()) { 398 case Stmt::ForStmtClass: 399 case Stmt::DoStmtClass: 400 case Stmt::WhileStmtClass: 401 return true; 402 default: 403 break; 404 } 405 406 return false; 407} 408 409PathDiagnosticLocation 410PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) { 411 assert(S && "Null Stmt *passed to getEnclosingStmtLocation"); 412 ParentMap &P = getParentMap(); 413 SourceManager &SMgr = getSourceManager(); 414 415 while (IsNested(S, P)) { 416 const Stmt *Parent = P.getParentIgnoreParens(S); 417 418 if (!Parent) 419 break; 420 421 switch (Parent->getStmtClass()) { 422 case Stmt::BinaryOperatorClass: { 423 const BinaryOperator *B = cast<BinaryOperator>(Parent); 424 if (B->isLogicalOp()) 425 return PathDiagnosticLocation(S, SMgr, LC); 426 break; 427 } 428 case Stmt::CompoundStmtClass: 429 case Stmt::StmtExprClass: 430 return PathDiagnosticLocation(S, SMgr, LC); 431 case Stmt::ChooseExprClass: 432 // Similar to '?' if we are referring to condition, just have the edge 433 // point to the entire choose expression. 434 if (cast<ChooseExpr>(Parent)->getCond() == S) 435 return PathDiagnosticLocation(Parent, SMgr, LC); 436 else 437 return PathDiagnosticLocation(S, SMgr, LC); 438 case Stmt::BinaryConditionalOperatorClass: 439 case Stmt::ConditionalOperatorClass: 440 // For '?', if we are referring to condition, just have the edge point 441 // to the entire '?' expression. 442 if (cast<AbstractConditionalOperator>(Parent)->getCond() == S) 443 return PathDiagnosticLocation(Parent, SMgr, LC); 444 else 445 return PathDiagnosticLocation(S, SMgr, LC); 446 case Stmt::DoStmtClass: 447 return PathDiagnosticLocation(S, SMgr, LC); 448 case Stmt::ForStmtClass: 449 if (cast<ForStmt>(Parent)->getBody() == S) 450 return PathDiagnosticLocation(S, SMgr, LC); 451 break; 452 case Stmt::IfStmtClass: 453 if (cast<IfStmt>(Parent)->getCond() != S) 454 return PathDiagnosticLocation(S, SMgr, LC); 455 break; 456 case Stmt::ObjCForCollectionStmtClass: 457 if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S) 458 return PathDiagnosticLocation(S, SMgr, LC); 459 break; 460 case Stmt::WhileStmtClass: 461 if (cast<WhileStmt>(Parent)->getCond() != S) 462 return PathDiagnosticLocation(S, SMgr, LC); 463 break; 464 default: 465 break; 466 } 467 468 S = Parent; 469 } 470 471 assert(S && "Cannot have null Stmt for PathDiagnosticLocation"); 472 473 // Special case: DeclStmts can appear in for statement declarations, in which 474 // case the ForStmt is the context. 475 if (isa<DeclStmt>(S)) { 476 if (const Stmt *Parent = P.getParent(S)) { 477 switch (Parent->getStmtClass()) { 478 case Stmt::ForStmtClass: 479 case Stmt::ObjCForCollectionStmtClass: 480 return PathDiagnosticLocation(Parent, SMgr, LC); 481 default: 482 break; 483 } 484 } 485 } 486 else if (isa<BinaryOperator>(S)) { 487 // Special case: the binary operator represents the initialization 488 // code in a for statement (this can happen when the variable being 489 // initialized is an old variable. 490 if (const ForStmt *FS = 491 dyn_cast_or_null<ForStmt>(P.getParentIgnoreParens(S))) { 492 if (FS->getInit() == S) 493 return PathDiagnosticLocation(FS, SMgr, LC); 494 } 495 } 496 497 return PathDiagnosticLocation(S, SMgr, LC); 498} 499 500//===----------------------------------------------------------------------===// 501// "Visitors only" path diagnostic generation algorithm. 502//===----------------------------------------------------------------------===// 503static bool GenerateVisitorsOnlyPathDiagnostic(PathDiagnostic &PD, 504 PathDiagnosticBuilder &PDB, 505 const ExplodedNode *N, 506 ArrayRef<BugReporterVisitor *> visitors) { 507 // All path generation skips the very first node (the error node). 508 // This is because there is special handling for the end-of-path note. 509 N = N->getFirstPred(); 510 if (!N) 511 return true; 512 513 BugReport *R = PDB.getBugReport(); 514 while (const ExplodedNode *Pred = N->getFirstPred()) { 515 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 516 E = visitors.end(); 517 I != E; ++I) { 518 // Visit all the node pairs, but throw the path pieces away. 519 PathDiagnosticPiece *Piece = (*I)->VisitNode(N, Pred, PDB, *R); 520 delete Piece; 521 } 522 523 N = Pred; 524 } 525 526 return R->isValid(); 527} 528 529//===----------------------------------------------------------------------===// 530// "Minimal" path diagnostic generation algorithm. 531//===----------------------------------------------------------------------===// 532typedef std::pair<PathDiagnosticCallPiece*, const ExplodedNode*> StackDiagPair; 533typedef SmallVector<StackDiagPair, 6> StackDiagVector; 534 535static void updateStackPiecesWithMessage(PathDiagnosticPiece *P, 536 StackDiagVector &CallStack) { 537 // If the piece contains a special message, add it to all the call 538 // pieces on the active stack. 539 if (PathDiagnosticEventPiece *ep = 540 dyn_cast<PathDiagnosticEventPiece>(P)) { 541 542 if (ep->hasCallStackHint()) 543 for (StackDiagVector::iterator I = CallStack.begin(), 544 E = CallStack.end(); I != E; ++I) { 545 PathDiagnosticCallPiece *CP = I->first; 546 const ExplodedNode *N = I->second; 547 std::string stackMsg = ep->getCallStackMessage(N); 548 549 // The last message on the path to final bug is the most important 550 // one. Since we traverse the path backwards, do not add the message 551 // if one has been previously added. 552 if (!CP->hasCallStackMessage()) 553 CP->setCallStackMessage(stackMsg); 554 } 555 } 556} 557 558static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM); 559 560static bool GenerateMinimalPathDiagnostic(PathDiagnostic& PD, 561 PathDiagnosticBuilder &PDB, 562 const ExplodedNode *N, 563 ArrayRef<BugReporterVisitor *> visitors) { 564 565 SourceManager& SMgr = PDB.getSourceManager(); 566 const LocationContext *LC = PDB.LC; 567 const ExplodedNode *NextNode = N->pred_empty() 568 ? NULL : *(N->pred_begin()); 569 570 StackDiagVector CallStack; 571 572 while (NextNode) { 573 N = NextNode; 574 PDB.LC = N->getLocationContext(); 575 NextNode = GetPredecessorNode(N); 576 577 ProgramPoint P = N->getLocation(); 578 579 do { 580 if (const CallExitEnd *CE = dyn_cast<CallExitEnd>(&P)) { 581 PathDiagnosticCallPiece *C = 582 PathDiagnosticCallPiece::construct(N, *CE, SMgr); 583 GRBugReporter& BR = PDB.getBugReporter(); 584 BR.addCallPieceLocationContextPair(C, CE->getCalleeContext()); 585 PD.getActivePath().push_front(C); 586 PD.pushActivePath(&C->path); 587 CallStack.push_back(StackDiagPair(C, N)); 588 break; 589 } 590 591 if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) { 592 // Flush all locations, and pop the active path. 593 bool VisitedEntireCall = PD.isWithinCall(); 594 PD.popActivePath(); 595 596 // Either we just added a bunch of stuff to the top-level path, or 597 // we have a previous CallExitEnd. If the former, it means that the 598 // path terminated within a function call. We must then take the 599 // current contents of the active path and place it within 600 // a new PathDiagnosticCallPiece. 601 PathDiagnosticCallPiece *C; 602 if (VisitedEntireCall) { 603 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 604 } else { 605 const Decl *Caller = CE->getLocationContext()->getDecl(); 606 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 607 GRBugReporter& BR = PDB.getBugReporter(); 608 BR.addCallPieceLocationContextPair(C, CE->getCalleeContext()); 609 } 610 611 C->setCallee(*CE, SMgr); 612 if (!CallStack.empty()) { 613 assert(CallStack.back().first == C); 614 CallStack.pop_back(); 615 } 616 break; 617 } 618 619 if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) { 620 const CFGBlock *Src = BE->getSrc(); 621 const CFGBlock *Dst = BE->getDst(); 622 const Stmt *T = Src->getTerminator(); 623 624 if (!T) 625 break; 626 627 PathDiagnosticLocation Start = 628 PathDiagnosticLocation::createBegin(T, SMgr, 629 N->getLocationContext()); 630 631 switch (T->getStmtClass()) { 632 default: 633 break; 634 635 case Stmt::GotoStmtClass: 636 case Stmt::IndirectGotoStmtClass: { 637 const Stmt *S = GetNextStmt(N); 638 639 if (!S) 640 break; 641 642 std::string sbuf; 643 llvm::raw_string_ostream os(sbuf); 644 const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S); 645 646 os << "Control jumps to line " 647 << End.asLocation().getExpansionLineNumber(); 648 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 649 Start, End, os.str())); 650 break; 651 } 652 653 case Stmt::SwitchStmtClass: { 654 // Figure out what case arm we took. 655 std::string sbuf; 656 llvm::raw_string_ostream os(sbuf); 657 658 if (const Stmt *S = Dst->getLabel()) { 659 PathDiagnosticLocation End(S, SMgr, LC); 660 661 switch (S->getStmtClass()) { 662 default: 663 os << "No cases match in the switch statement. " 664 "Control jumps to line " 665 << End.asLocation().getExpansionLineNumber(); 666 break; 667 case Stmt::DefaultStmtClass: 668 os << "Control jumps to the 'default' case at line " 669 << End.asLocation().getExpansionLineNumber(); 670 break; 671 672 case Stmt::CaseStmtClass: { 673 os << "Control jumps to 'case "; 674 const CaseStmt *Case = cast<CaseStmt>(S); 675 const Expr *LHS = Case->getLHS()->IgnoreParenCasts(); 676 677 // Determine if it is an enum. 678 bool GetRawInt = true; 679 680 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS)) { 681 // FIXME: Maybe this should be an assertion. Are there cases 682 // were it is not an EnumConstantDecl? 683 const EnumConstantDecl *D = 684 dyn_cast<EnumConstantDecl>(DR->getDecl()); 685 686 if (D) { 687 GetRawInt = false; 688 os << *D; 689 } 690 } 691 692 if (GetRawInt) 693 os << LHS->EvaluateKnownConstInt(PDB.getASTContext()); 694 695 os << ":' at line " 696 << End.asLocation().getExpansionLineNumber(); 697 break; 698 } 699 } 700 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 701 Start, End, os.str())); 702 } 703 else { 704 os << "'Default' branch taken. "; 705 const PathDiagnosticLocation &End = PDB.ExecutionContinues(os, N); 706 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 707 Start, End, os.str())); 708 } 709 710 break; 711 } 712 713 case Stmt::BreakStmtClass: 714 case Stmt::ContinueStmtClass: { 715 std::string sbuf; 716 llvm::raw_string_ostream os(sbuf); 717 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 718 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 719 Start, End, os.str())); 720 break; 721 } 722 723 // Determine control-flow for ternary '?'. 724 case Stmt::BinaryConditionalOperatorClass: 725 case Stmt::ConditionalOperatorClass: { 726 std::string sbuf; 727 llvm::raw_string_ostream os(sbuf); 728 os << "'?' condition is "; 729 730 if (*(Src->succ_begin()+1) == Dst) 731 os << "false"; 732 else 733 os << "true"; 734 735 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 736 737 if (const Stmt *S = End.asStmt()) 738 End = PDB.getEnclosingStmtLocation(S); 739 740 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 741 Start, End, os.str())); 742 break; 743 } 744 745 // Determine control-flow for short-circuited '&&' and '||'. 746 case Stmt::BinaryOperatorClass: { 747 if (!PDB.supportsLogicalOpControlFlow()) 748 break; 749 750 const BinaryOperator *B = cast<BinaryOperator>(T); 751 std::string sbuf; 752 llvm::raw_string_ostream os(sbuf); 753 os << "Left side of '"; 754 755 if (B->getOpcode() == BO_LAnd) { 756 os << "&&" << "' is "; 757 758 if (*(Src->succ_begin()+1) == Dst) { 759 os << "false"; 760 PathDiagnosticLocation End(B->getLHS(), SMgr, LC); 761 PathDiagnosticLocation Start = 762 PathDiagnosticLocation::createOperatorLoc(B, SMgr); 763 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 764 Start, End, os.str())); 765 } 766 else { 767 os << "true"; 768 PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); 769 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 770 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 771 Start, End, os.str())); 772 } 773 } 774 else { 775 assert(B->getOpcode() == BO_LOr); 776 os << "||" << "' is "; 777 778 if (*(Src->succ_begin()+1) == Dst) { 779 os << "false"; 780 PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); 781 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 782 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 783 Start, End, os.str())); 784 } 785 else { 786 os << "true"; 787 PathDiagnosticLocation End(B->getLHS(), SMgr, LC); 788 PathDiagnosticLocation Start = 789 PathDiagnosticLocation::createOperatorLoc(B, SMgr); 790 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 791 Start, End, os.str())); 792 } 793 } 794 795 break; 796 } 797 798 case Stmt::DoStmtClass: { 799 if (*(Src->succ_begin()) == Dst) { 800 std::string sbuf; 801 llvm::raw_string_ostream os(sbuf); 802 803 os << "Loop condition is true. "; 804 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 805 806 if (const Stmt *S = End.asStmt()) 807 End = PDB.getEnclosingStmtLocation(S); 808 809 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 810 Start, End, os.str())); 811 } 812 else { 813 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 814 815 if (const Stmt *S = End.asStmt()) 816 End = PDB.getEnclosingStmtLocation(S); 817 818 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 819 Start, End, "Loop condition is false. Exiting loop")); 820 } 821 822 break; 823 } 824 825 case Stmt::WhileStmtClass: 826 case Stmt::ForStmtClass: { 827 if (*(Src->succ_begin()+1) == Dst) { 828 std::string sbuf; 829 llvm::raw_string_ostream os(sbuf); 830 831 os << "Loop condition is false. "; 832 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 833 if (const Stmt *S = End.asStmt()) 834 End = PDB.getEnclosingStmtLocation(S); 835 836 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 837 Start, End, os.str())); 838 } 839 else { 840 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 841 if (const Stmt *S = End.asStmt()) 842 End = PDB.getEnclosingStmtLocation(S); 843 844 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 845 Start, End, "Loop condition is true. Entering loop body")); 846 } 847 848 break; 849 } 850 851 case Stmt::IfStmtClass: { 852 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 853 854 if (const Stmt *S = End.asStmt()) 855 End = PDB.getEnclosingStmtLocation(S); 856 857 if (*(Src->succ_begin()+1) == Dst) 858 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 859 Start, End, "Taking false branch")); 860 else 861 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 862 Start, End, "Taking true branch")); 863 864 break; 865 } 866 } 867 } 868 } while(0); 869 870 if (NextNode) { 871 // Add diagnostic pieces from custom visitors. 872 BugReport *R = PDB.getBugReport(); 873 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 874 E = visitors.end(); 875 I != E; ++I) { 876 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 877 PD.getActivePath().push_front(p); 878 updateStackPiecesWithMessage(p, CallStack); 879 } 880 } 881 } 882 } 883 884 if (!PDB.getBugReport()->isValid()) 885 return false; 886 887 // After constructing the full PathDiagnostic, do a pass over it to compact 888 // PathDiagnosticPieces that occur within a macro. 889 CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager()); 890 return true; 891} 892 893//===----------------------------------------------------------------------===// 894// "Extensive" PathDiagnostic generation. 895//===----------------------------------------------------------------------===// 896 897static bool IsControlFlowExpr(const Stmt *S) { 898 const Expr *E = dyn_cast<Expr>(S); 899 900 if (!E) 901 return false; 902 903 E = E->IgnoreParenCasts(); 904 905 if (isa<AbstractConditionalOperator>(E)) 906 return true; 907 908 if (const BinaryOperator *B = dyn_cast<BinaryOperator>(E)) 909 if (B->isLogicalOp()) 910 return true; 911 912 return false; 913} 914 915namespace { 916class ContextLocation : public PathDiagnosticLocation { 917 bool IsDead; 918public: 919 ContextLocation(const PathDiagnosticLocation &L, bool isdead = false) 920 : PathDiagnosticLocation(L), IsDead(isdead) {} 921 922 void markDead() { IsDead = true; } 923 bool isDead() const { return IsDead; } 924}; 925 926class EdgeBuilder { 927 std::vector<ContextLocation> CLocs; 928 typedef std::vector<ContextLocation>::iterator iterator; 929 PathDiagnostic &PD; 930 PathDiagnosticBuilder &PDB; 931 PathDiagnosticLocation PrevLoc; 932 933 bool IsConsumedExpr(const PathDiagnosticLocation &L); 934 935 bool containsLocation(const PathDiagnosticLocation &Container, 936 const PathDiagnosticLocation &Containee); 937 938 PathDiagnosticLocation getContextLocation(const PathDiagnosticLocation &L); 939 940 PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L, 941 bool firstCharOnly = false) { 942 if (const Stmt *S = L.asStmt()) { 943 const Stmt *Original = S; 944 while (1) { 945 // Adjust the location for some expressions that are best referenced 946 // by one of their subexpressions. 947 switch (S->getStmtClass()) { 948 default: 949 break; 950 case Stmt::ParenExprClass: 951 case Stmt::GenericSelectionExprClass: 952 S = cast<Expr>(S)->IgnoreParens(); 953 firstCharOnly = true; 954 continue; 955 case Stmt::BinaryConditionalOperatorClass: 956 case Stmt::ConditionalOperatorClass: 957 S = cast<AbstractConditionalOperator>(S)->getCond(); 958 firstCharOnly = true; 959 continue; 960 case Stmt::ChooseExprClass: 961 S = cast<ChooseExpr>(S)->getCond(); 962 firstCharOnly = true; 963 continue; 964 case Stmt::BinaryOperatorClass: 965 S = cast<BinaryOperator>(S)->getLHS(); 966 firstCharOnly = true; 967 continue; 968 } 969 970 break; 971 } 972 973 if (S != Original) 974 L = PathDiagnosticLocation(S, L.getManager(), PDB.LC); 975 } 976 977 if (firstCharOnly) 978 L = PathDiagnosticLocation::createSingleLocation(L); 979 980 return L; 981 } 982 983 void popLocation() { 984 if (!CLocs.back().isDead() && CLocs.back().asLocation().isFileID()) { 985 // For contexts, we only one the first character as the range. 986 rawAddEdge(cleanUpLocation(CLocs.back(), true)); 987 } 988 CLocs.pop_back(); 989 } 990 991public: 992 EdgeBuilder(PathDiagnostic &pd, PathDiagnosticBuilder &pdb) 993 : PD(pd), PDB(pdb) { 994 995 // If the PathDiagnostic already has pieces, add the enclosing statement 996 // of the first piece as a context as well. 997 if (!PD.path.empty()) { 998 PrevLoc = (*PD.path.begin())->getLocation(); 999 1000 if (const Stmt *S = PrevLoc.asStmt()) 1001 addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 1002 } 1003 } 1004 1005 ~EdgeBuilder() { 1006 while (!CLocs.empty()) popLocation(); 1007 1008 // Finally, add an initial edge from the start location of the first 1009 // statement (if it doesn't already exist). 1010 PathDiagnosticLocation L = PathDiagnosticLocation::createDeclBegin( 1011 PDB.LC, 1012 PDB.getSourceManager()); 1013 if (L.isValid()) 1014 rawAddEdge(L); 1015 } 1016 1017 void flushLocations() { 1018 while (!CLocs.empty()) 1019 popLocation(); 1020 PrevLoc = PathDiagnosticLocation(); 1021 } 1022 1023 void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false); 1024 1025 void rawAddEdge(PathDiagnosticLocation NewLoc); 1026 1027 void addContext(const Stmt *S); 1028 void addContext(const PathDiagnosticLocation &L); 1029 void addExtendedContext(const Stmt *S); 1030}; 1031} // end anonymous namespace 1032 1033 1034PathDiagnosticLocation 1035EdgeBuilder::getContextLocation(const PathDiagnosticLocation &L) { 1036 if (const Stmt *S = L.asStmt()) { 1037 if (IsControlFlowExpr(S)) 1038 return L; 1039 1040 return PDB.getEnclosingStmtLocation(S); 1041 } 1042 1043 return L; 1044} 1045 1046bool EdgeBuilder::containsLocation(const PathDiagnosticLocation &Container, 1047 const PathDiagnosticLocation &Containee) { 1048 1049 if (Container == Containee) 1050 return true; 1051 1052 if (Container.asDecl()) 1053 return true; 1054 1055 if (const Stmt *S = Containee.asStmt()) 1056 if (const Stmt *ContainerS = Container.asStmt()) { 1057 while (S) { 1058 if (S == ContainerS) 1059 return true; 1060 S = PDB.getParent(S); 1061 } 1062 return false; 1063 } 1064 1065 // Less accurate: compare using source ranges. 1066 SourceRange ContainerR = Container.asRange(); 1067 SourceRange ContaineeR = Containee.asRange(); 1068 1069 SourceManager &SM = PDB.getSourceManager(); 1070 SourceLocation ContainerRBeg = SM.getExpansionLoc(ContainerR.getBegin()); 1071 SourceLocation ContainerREnd = SM.getExpansionLoc(ContainerR.getEnd()); 1072 SourceLocation ContaineeRBeg = SM.getExpansionLoc(ContaineeR.getBegin()); 1073 SourceLocation ContaineeREnd = SM.getExpansionLoc(ContaineeR.getEnd()); 1074 1075 unsigned ContainerBegLine = SM.getExpansionLineNumber(ContainerRBeg); 1076 unsigned ContainerEndLine = SM.getExpansionLineNumber(ContainerREnd); 1077 unsigned ContaineeBegLine = SM.getExpansionLineNumber(ContaineeRBeg); 1078 unsigned ContaineeEndLine = SM.getExpansionLineNumber(ContaineeREnd); 1079 1080 assert(ContainerBegLine <= ContainerEndLine); 1081 assert(ContaineeBegLine <= ContaineeEndLine); 1082 1083 return (ContainerBegLine <= ContaineeBegLine && 1084 ContainerEndLine >= ContaineeEndLine && 1085 (ContainerBegLine != ContaineeBegLine || 1086 SM.getExpansionColumnNumber(ContainerRBeg) <= 1087 SM.getExpansionColumnNumber(ContaineeRBeg)) && 1088 (ContainerEndLine != ContaineeEndLine || 1089 SM.getExpansionColumnNumber(ContainerREnd) >= 1090 SM.getExpansionColumnNumber(ContaineeREnd))); 1091} 1092 1093void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) { 1094 if (!PrevLoc.isValid()) { 1095 PrevLoc = NewLoc; 1096 return; 1097 } 1098 1099 const PathDiagnosticLocation &NewLocClean = cleanUpLocation(NewLoc); 1100 const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc); 1101 1102 if (PrevLocClean.asLocation().isInvalid()) { 1103 PrevLoc = NewLoc; 1104 return; 1105 } 1106 1107 if (NewLocClean.asLocation() == PrevLocClean.asLocation()) 1108 return; 1109 1110 // FIXME: Ignore intra-macro edges for now. 1111 if (NewLocClean.asLocation().getExpansionLoc() == 1112 PrevLocClean.asLocation().getExpansionLoc()) 1113 return; 1114 1115 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(NewLocClean, PrevLocClean)); 1116 PrevLoc = NewLoc; 1117} 1118 1119void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd) { 1120 1121 if (!alwaysAdd && NewLoc.asLocation().isMacroID()) 1122 return; 1123 1124 const PathDiagnosticLocation &CLoc = getContextLocation(NewLoc); 1125 1126 while (!CLocs.empty()) { 1127 ContextLocation &TopContextLoc = CLocs.back(); 1128 1129 // Is the top location context the same as the one for the new location? 1130 if (TopContextLoc == CLoc) { 1131 if (alwaysAdd) { 1132 if (IsConsumedExpr(TopContextLoc) && 1133 !IsControlFlowExpr(TopContextLoc.asStmt())) 1134 TopContextLoc.markDead(); 1135 1136 rawAddEdge(NewLoc); 1137 } 1138 1139 return; 1140 } 1141 1142 if (containsLocation(TopContextLoc, CLoc)) { 1143 if (alwaysAdd) { 1144 rawAddEdge(NewLoc); 1145 1146 if (IsConsumedExpr(CLoc) && !IsControlFlowExpr(CLoc.asStmt())) { 1147 CLocs.push_back(ContextLocation(CLoc, true)); 1148 return; 1149 } 1150 } 1151 1152 CLocs.push_back(CLoc); 1153 return; 1154 } 1155 1156 // Context does not contain the location. Flush it. 1157 popLocation(); 1158 } 1159 1160 // If we reach here, there is no enclosing context. Just add the edge. 1161 rawAddEdge(NewLoc); 1162} 1163 1164bool EdgeBuilder::IsConsumedExpr(const PathDiagnosticLocation &L) { 1165 if (const Expr *X = dyn_cast_or_null<Expr>(L.asStmt())) 1166 return PDB.getParentMap().isConsumedExpr(X) && !IsControlFlowExpr(X); 1167 1168 return false; 1169} 1170 1171void EdgeBuilder::addExtendedContext(const Stmt *S) { 1172 if (!S) 1173 return; 1174 1175 const Stmt *Parent = PDB.getParent(S); 1176 while (Parent) { 1177 if (isa<CompoundStmt>(Parent)) 1178 Parent = PDB.getParent(Parent); 1179 else 1180 break; 1181 } 1182 1183 if (Parent) { 1184 switch (Parent->getStmtClass()) { 1185 case Stmt::DoStmtClass: 1186 case Stmt::ObjCAtSynchronizedStmtClass: 1187 addContext(Parent); 1188 default: 1189 break; 1190 } 1191 } 1192 1193 addContext(S); 1194} 1195 1196void EdgeBuilder::addContext(const Stmt *S) { 1197 if (!S) 1198 return; 1199 1200 PathDiagnosticLocation L(S, PDB.getSourceManager(), PDB.LC); 1201 addContext(L); 1202} 1203 1204void EdgeBuilder::addContext(const PathDiagnosticLocation &L) { 1205 while (!CLocs.empty()) { 1206 const PathDiagnosticLocation &TopContextLoc = CLocs.back(); 1207 1208 // Is the top location context the same as the one for the new location? 1209 if (TopContextLoc == L) 1210 return; 1211 1212 if (containsLocation(TopContextLoc, L)) { 1213 CLocs.push_back(L); 1214 return; 1215 } 1216 1217 // Context does not contain the location. Flush it. 1218 popLocation(); 1219 } 1220 1221 CLocs.push_back(L); 1222} 1223 1224// Cone-of-influence: support the reverse propagation of "interesting" symbols 1225// and values by tracing interesting calculations backwards through evaluated 1226// expressions along a path. This is probably overly complicated, but the idea 1227// is that if an expression computed an "interesting" value, the child 1228// expressions are are also likely to be "interesting" as well (which then 1229// propagates to the values they in turn compute). This reverse propagation 1230// is needed to track interesting correlations across function call boundaries, 1231// where formal arguments bind to actual arguments, etc. This is also needed 1232// because the constraint solver sometimes simplifies certain symbolic values 1233// into constants when appropriate, and this complicates reasoning about 1234// interesting values. 1235typedef llvm::DenseSet<const Expr *> InterestingExprs; 1236 1237static void reversePropagateIntererstingSymbols(BugReport &R, 1238 InterestingExprs &IE, 1239 const ProgramState *State, 1240 const Expr *Ex, 1241 const LocationContext *LCtx) { 1242 SVal V = State->getSVal(Ex, LCtx); 1243 if (!(R.isInteresting(V) || IE.count(Ex))) 1244 return; 1245 1246 switch (Ex->getStmtClass()) { 1247 default: 1248 if (!isa<CastExpr>(Ex)) 1249 break; 1250 // Fall through. 1251 case Stmt::BinaryOperatorClass: 1252 case Stmt::UnaryOperatorClass: { 1253 for (Stmt::const_child_iterator CI = Ex->child_begin(), 1254 CE = Ex->child_end(); 1255 CI != CE; ++CI) { 1256 if (const Expr *child = dyn_cast_or_null<Expr>(*CI)) { 1257 IE.insert(child); 1258 SVal ChildV = State->getSVal(child, LCtx); 1259 R.markInteresting(ChildV); 1260 } 1261 break; 1262 } 1263 } 1264 } 1265 1266 R.markInteresting(V); 1267} 1268 1269static void reversePropagateInterestingSymbols(BugReport &R, 1270 InterestingExprs &IE, 1271 const ProgramState *State, 1272 const LocationContext *CalleeCtx, 1273 const LocationContext *CallerCtx) 1274{ 1275 // FIXME: Handle non-CallExpr-based CallEvents. 1276 const StackFrameContext *Callee = CalleeCtx->getCurrentStackFrame(); 1277 const Stmt *CallSite = Callee->getCallSite(); 1278 if (const CallExpr *CE = dyn_cast_or_null<CallExpr>(CallSite)) { 1279 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CalleeCtx->getDecl())) { 1280 FunctionDecl::param_const_iterator PI = FD->param_begin(), 1281 PE = FD->param_end(); 1282 CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end(); 1283 for (; AI != AE && PI != PE; ++AI, ++PI) { 1284 if (const Expr *ArgE = *AI) { 1285 if (const ParmVarDecl *PD = *PI) { 1286 Loc LV = State->getLValue(PD, CalleeCtx); 1287 if (R.isInteresting(LV) || R.isInteresting(State->getRawSVal(LV))) 1288 IE.insert(ArgE); 1289 } 1290 } 1291 } 1292 } 1293 } 1294} 1295 1296static bool GenerateExtensivePathDiagnostic(PathDiagnostic& PD, 1297 PathDiagnosticBuilder &PDB, 1298 const ExplodedNode *N, 1299 ArrayRef<BugReporterVisitor *> visitors) { 1300 EdgeBuilder EB(PD, PDB); 1301 const SourceManager& SM = PDB.getSourceManager(); 1302 StackDiagVector CallStack; 1303 InterestingExprs IE; 1304 1305 const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin()); 1306 while (NextNode) { 1307 N = NextNode; 1308 NextNode = GetPredecessorNode(N); 1309 ProgramPoint P = N->getLocation(); 1310 1311 do { 1312 if (const PostStmt *PS = dyn_cast<PostStmt>(&P)) { 1313 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1314 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1315 N->getState().getPtr(), Ex, 1316 N->getLocationContext()); 1317 } 1318 1319 if (const CallExitEnd *CE = dyn_cast<CallExitEnd>(&P)) { 1320 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1321 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1322 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1323 N->getState().getPtr(), Ex, 1324 N->getLocationContext()); 1325 } 1326 1327 PathDiagnosticCallPiece *C = 1328 PathDiagnosticCallPiece::construct(N, *CE, SM); 1329 GRBugReporter& BR = PDB.getBugReporter(); 1330 BR.addCallPieceLocationContextPair(C, CE->getCalleeContext()); 1331 1332 EB.addEdge(C->callReturn, true); 1333 EB.flushLocations(); 1334 1335 PD.getActivePath().push_front(C); 1336 PD.pushActivePath(&C->path); 1337 CallStack.push_back(StackDiagPair(C, N)); 1338 break; 1339 } 1340 1341 // Pop the call hierarchy if we are done walking the contents 1342 // of a function call. 1343 if (const CallEnter *CE = dyn_cast<CallEnter>(&P)) { 1344 // Add an edge to the start of the function. 1345 const Decl *D = CE->getCalleeContext()->getDecl(); 1346 PathDiagnosticLocation pos = 1347 PathDiagnosticLocation::createBegin(D, SM); 1348 EB.addEdge(pos); 1349 1350 // Flush all locations, and pop the active path. 1351 bool VisitedEntireCall = PD.isWithinCall(); 1352 EB.flushLocations(); 1353 PD.popActivePath(); 1354 PDB.LC = N->getLocationContext(); 1355 1356 // Either we just added a bunch of stuff to the top-level path, or 1357 // we have a previous CallExitEnd. If the former, it means that the 1358 // path terminated within a function call. We must then take the 1359 // current contents of the active path and place it within 1360 // a new PathDiagnosticCallPiece. 1361 PathDiagnosticCallPiece *C; 1362 if (VisitedEntireCall) { 1363 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 1364 } else { 1365 const Decl *Caller = CE->getLocationContext()->getDecl(); 1366 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1367 GRBugReporter& BR = PDB.getBugReporter(); 1368 BR.addCallPieceLocationContextPair(C, CE->getCalleeContext()); 1369 } 1370 1371 C->setCallee(*CE, SM); 1372 EB.addContext(C->getLocation()); 1373 1374 if (!CallStack.empty()) { 1375 assert(CallStack.back().first == C); 1376 CallStack.pop_back(); 1377 } 1378 break; 1379 } 1380 1381 // Note that is important that we update the LocationContext 1382 // after looking at CallExits. CallExit basically adds an 1383 // edge in the *caller*, so we don't want to update the LocationContext 1384 // too soon. 1385 PDB.LC = N->getLocationContext(); 1386 1387 // Block edges. 1388 if (const BlockEdge *BE = dyn_cast<BlockEdge>(&P)) { 1389 // Does this represent entering a call? If so, look at propagating 1390 // interesting symbols across call boundaries. 1391 if (NextNode) { 1392 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1393 const LocationContext *CalleeCtx = PDB.LC; 1394 if (CallerCtx != CalleeCtx) { 1395 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1396 N->getState().getPtr(), 1397 CalleeCtx, CallerCtx); 1398 } 1399 } 1400 1401 // Are we jumping to the head of a loop? Add a special diagnostic. 1402 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1403 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1404 const CompoundStmt *CS = NULL; 1405 1406 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1407 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1408 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1409 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1410 1411 PathDiagnosticEventPiece *p = 1412 new PathDiagnosticEventPiece(L, 1413 "Looping back to the head of the loop"); 1414 p->setPrunable(true); 1415 1416 EB.addEdge(p->getLocation(), true); 1417 PD.getActivePath().push_front(p); 1418 1419 if (CS) { 1420 PathDiagnosticLocation BL = 1421 PathDiagnosticLocation::createEndBrace(CS, SM); 1422 EB.addEdge(BL); 1423 } 1424 } 1425 1426 if (const Stmt *Term = BE->getSrc()->getTerminator()) 1427 EB.addContext(Term); 1428 1429 break; 1430 } 1431 1432 if (const BlockEntrance *BE = dyn_cast<BlockEntrance>(&P)) { 1433 CFGElement First = BE->getFirstElement(); 1434 if (const CFGStmt *S = First.getAs<CFGStmt>()) { 1435 const Stmt *stmt = S->getStmt(); 1436 if (IsControlFlowExpr(stmt)) { 1437 // Add the proper context for '&&', '||', and '?'. 1438 EB.addContext(stmt); 1439 } 1440 else 1441 EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt()); 1442 } 1443 1444 break; 1445 } 1446 1447 1448 } while (0); 1449 1450 if (!NextNode) 1451 continue; 1452 1453 // Add pieces from custom visitors. 1454 BugReport *R = PDB.getBugReport(); 1455 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1456 E = visitors.end(); 1457 I != E; ++I) { 1458 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 1459 const PathDiagnosticLocation &Loc = p->getLocation(); 1460 EB.addEdge(Loc, true); 1461 PD.getActivePath().push_front(p); 1462 updateStackPiecesWithMessage(p, CallStack); 1463 1464 if (const Stmt *S = Loc.asStmt()) 1465 EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 1466 } 1467 } 1468 } 1469 1470 return PDB.getBugReport()->isValid(); 1471} 1472 1473//===----------------------------------------------------------------------===// 1474// Methods for BugType and subclasses. 1475//===----------------------------------------------------------------------===// 1476BugType::~BugType() { } 1477 1478void BugType::FlushReports(BugReporter &BR) {} 1479 1480void BuiltinBug::anchor() {} 1481 1482//===----------------------------------------------------------------------===// 1483// Methods for BugReport and subclasses. 1484//===----------------------------------------------------------------------===// 1485 1486void BugReport::NodeResolver::anchor() {} 1487 1488void BugReport::addVisitor(BugReporterVisitor* visitor) { 1489 if (!visitor) 1490 return; 1491 1492 llvm::FoldingSetNodeID ID; 1493 visitor->Profile(ID); 1494 void *InsertPos; 1495 1496 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) { 1497 delete visitor; 1498 return; 1499 } 1500 1501 CallbacksSet.InsertNode(visitor, InsertPos); 1502 Callbacks.push_back(visitor); 1503 ++ConfigurationChangeToken; 1504} 1505 1506BugReport::~BugReport() { 1507 for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) { 1508 delete *I; 1509 } 1510 while (!interestingSymbols.empty()) { 1511 popInterestingSymbolsAndRegions(); 1512 } 1513} 1514 1515const Decl *BugReport::getDeclWithIssue() const { 1516 if (DeclWithIssue) 1517 return DeclWithIssue; 1518 1519 const ExplodedNode *N = getErrorNode(); 1520 if (!N) 1521 return 0; 1522 1523 const LocationContext *LC = N->getLocationContext(); 1524 return LC->getCurrentStackFrame()->getDecl(); 1525} 1526 1527void BugReport::Profile(llvm::FoldingSetNodeID& hash) const { 1528 hash.AddPointer(&BT); 1529 hash.AddString(Description); 1530 PathDiagnosticLocation UL = getUniqueingLocation(); 1531 if (UL.isValid()) { 1532 UL.Profile(hash); 1533 } else if (Location.isValid()) { 1534 Location.Profile(hash); 1535 } else { 1536 assert(ErrorNode); 1537 hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode)); 1538 } 1539 1540 for (SmallVectorImpl<SourceRange>::const_iterator I = 1541 Ranges.begin(), E = Ranges.end(); I != E; ++I) { 1542 const SourceRange range = *I; 1543 if (!range.isValid()) 1544 continue; 1545 hash.AddInteger(range.getBegin().getRawEncoding()); 1546 hash.AddInteger(range.getEnd().getRawEncoding()); 1547 } 1548} 1549 1550void BugReport::markInteresting(SymbolRef sym) { 1551 if (!sym) 1552 return; 1553 1554 // If the symbol wasn't already in our set, note a configuration change. 1555 if (getInterestingSymbols().insert(sym).second) 1556 ++ConfigurationChangeToken; 1557 1558 if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym)) 1559 getInterestingRegions().insert(meta->getRegion()); 1560} 1561 1562void BugReport::markInteresting(const MemRegion *R) { 1563 if (!R) 1564 return; 1565 1566 // If the base region wasn't already in our set, note a configuration change. 1567 R = R->getBaseRegion(); 1568 if (getInterestingRegions().insert(R).second) 1569 ++ConfigurationChangeToken; 1570 1571 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 1572 getInterestingSymbols().insert(SR->getSymbol()); 1573} 1574 1575void BugReport::markInteresting(SVal V) { 1576 markInteresting(V.getAsRegion()); 1577 markInteresting(V.getAsSymbol()); 1578} 1579 1580void BugReport::markInteresting(const LocationContext *LC) { 1581 if (!LC) 1582 return; 1583 InterestingLocationContexts.insert(LC); 1584} 1585 1586bool BugReport::isInteresting(SVal V) { 1587 return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol()); 1588} 1589 1590bool BugReport::isInteresting(SymbolRef sym) { 1591 if (!sym) 1592 return false; 1593 // We don't currently consider metadata symbols to be interesting 1594 // even if we know their region is interesting. Is that correct behavior? 1595 return getInterestingSymbols().count(sym); 1596} 1597 1598bool BugReport::isInteresting(const MemRegion *R) { 1599 if (!R) 1600 return false; 1601 R = R->getBaseRegion(); 1602 bool b = getInterestingRegions().count(R); 1603 if (b) 1604 return true; 1605 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 1606 return getInterestingSymbols().count(SR->getSymbol()); 1607 return false; 1608} 1609 1610bool BugReport::isInteresting(const LocationContext *LC) { 1611 if (!LC) 1612 return false; 1613 return InterestingLocationContexts.count(LC); 1614} 1615 1616void BugReport::lazyInitializeInterestingSets() { 1617 if (interestingSymbols.empty()) { 1618 interestingSymbols.push_back(new Symbols()); 1619 interestingRegions.push_back(new Regions()); 1620 } 1621} 1622 1623BugReport::Symbols &BugReport::getInterestingSymbols() { 1624 lazyInitializeInterestingSets(); 1625 return *interestingSymbols.back(); 1626} 1627 1628BugReport::Regions &BugReport::getInterestingRegions() { 1629 lazyInitializeInterestingSets(); 1630 return *interestingRegions.back(); 1631} 1632 1633void BugReport::pushInterestingSymbolsAndRegions() { 1634 interestingSymbols.push_back(new Symbols(getInterestingSymbols())); 1635 interestingRegions.push_back(new Regions(getInterestingRegions())); 1636} 1637 1638void BugReport::popInterestingSymbolsAndRegions() { 1639 delete interestingSymbols.back(); 1640 interestingSymbols.pop_back(); 1641 delete interestingRegions.back(); 1642 interestingRegions.pop_back(); 1643} 1644 1645const Stmt *BugReport::getStmt() const { 1646 if (!ErrorNode) 1647 return 0; 1648 1649 ProgramPoint ProgP = ErrorNode->getLocation(); 1650 const Stmt *S = NULL; 1651 1652 if (BlockEntrance *BE = dyn_cast<BlockEntrance>(&ProgP)) { 1653 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit(); 1654 if (BE->getBlock() == &Exit) 1655 S = GetPreviousStmt(ErrorNode); 1656 } 1657 if (!S) 1658 S = GetStmt(ProgP); 1659 1660 return S; 1661} 1662 1663std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator> 1664BugReport::getRanges() { 1665 // If no custom ranges, add the range of the statement corresponding to 1666 // the error node. 1667 if (Ranges.empty()) { 1668 if (const Expr *E = dyn_cast_or_null<Expr>(getStmt())) 1669 addRange(E->getSourceRange()); 1670 else 1671 return std::make_pair(ranges_iterator(), ranges_iterator()); 1672 } 1673 1674 // User-specified absence of range info. 1675 if (Ranges.size() == 1 && !Ranges.begin()->isValid()) 1676 return std::make_pair(ranges_iterator(), ranges_iterator()); 1677 1678 return std::make_pair(Ranges.begin(), Ranges.end()); 1679} 1680 1681PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const { 1682 if (ErrorNode) { 1683 assert(!Location.isValid() && 1684 "Either Location or ErrorNode should be specified but not both."); 1685 1686 if (const Stmt *S = GetCurrentOrPreviousStmt(ErrorNode)) { 1687 const LocationContext *LC = ErrorNode->getLocationContext(); 1688 1689 // For member expressions, return the location of the '.' or '->'. 1690 if (const MemberExpr *ME = dyn_cast<MemberExpr>(S)) 1691 return PathDiagnosticLocation::createMemberLoc(ME, SM); 1692 // For binary operators, return the location of the operator. 1693 if (const BinaryOperator *B = dyn_cast<BinaryOperator>(S)) 1694 return PathDiagnosticLocation::createOperatorLoc(B, SM); 1695 1696 if (isa<PostStmtPurgeDeadSymbols>(ErrorNode->getLocation())) 1697 return PathDiagnosticLocation::createEnd(S, SM, LC); 1698 1699 return PathDiagnosticLocation::createBegin(S, SM, LC); 1700 } 1701 } else { 1702 assert(Location.isValid()); 1703 return Location; 1704 } 1705 1706 return PathDiagnosticLocation(); 1707} 1708 1709//===----------------------------------------------------------------------===// 1710// Methods for BugReporter and subclasses. 1711//===----------------------------------------------------------------------===// 1712 1713BugReportEquivClass::~BugReportEquivClass() { } 1714GRBugReporter::~GRBugReporter() { } 1715BugReporterData::~BugReporterData() {} 1716 1717ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); } 1718 1719ProgramStateManager& 1720GRBugReporter::getStateManager() { return Eng.getStateManager(); } 1721 1722BugReporter::~BugReporter() { 1723 FlushReports(); 1724 1725 // Free the bug reports we are tracking. 1726 typedef std::vector<BugReportEquivClass *> ContTy; 1727 for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end(); 1728 I != E; ++I) { 1729 delete *I; 1730 } 1731} 1732 1733void BugReporter::FlushReports() { 1734 if (BugTypes.isEmpty()) 1735 return; 1736 1737 // First flush the warnings for each BugType. This may end up creating new 1738 // warnings and new BugTypes. 1739 // FIXME: Only NSErrorChecker needs BugType's FlushReports. 1740 // Turn NSErrorChecker into a proper checker and remove this. 1741 SmallVector<const BugType*, 16> bugTypes; 1742 for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I) 1743 bugTypes.push_back(*I); 1744 for (SmallVector<const BugType*, 16>::iterator 1745 I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I) 1746 const_cast<BugType*>(*I)->FlushReports(*this); 1747 1748 // We need to flush reports in deterministic order to ensure the order 1749 // of the reports is consistent between runs. 1750 typedef std::vector<BugReportEquivClass *> ContVecTy; 1751 for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.end(); 1752 EI != EE; ++EI){ 1753 BugReportEquivClass& EQ = **EI; 1754 FlushReport(EQ); 1755 } 1756 1757 // BugReporter owns and deletes only BugTypes created implicitly through 1758 // EmitBasicReport. 1759 // FIXME: There are leaks from checkers that assume that the BugTypes they 1760 // create will be destroyed by the BugReporter. 1761 for (llvm::StringMap<BugType*>::iterator 1762 I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I) 1763 delete I->second; 1764 1765 // Remove all references to the BugType objects. 1766 BugTypes = F.getEmptySet(); 1767} 1768 1769//===----------------------------------------------------------------------===// 1770// PathDiagnostics generation. 1771//===----------------------------------------------------------------------===// 1772 1773static std::pair<std::pair<ExplodedGraph*, NodeBackMap*>, 1774 std::pair<ExplodedNode*, unsigned> > 1775MakeReportGraph(const ExplodedGraph* G, 1776 SmallVectorImpl<const ExplodedNode*> &nodes) { 1777 1778 // Create the trimmed graph. It will contain the shortest paths from the 1779 // error nodes to the root. In the new graph we should only have one 1780 // error node unless there are two or more error nodes with the same minimum 1781 // path length. 1782 ExplodedGraph* GTrim; 1783 InterExplodedGraphMap* NMap; 1784 1785 llvm::DenseMap<const void*, const void*> InverseMap; 1786 llvm::tie(GTrim, NMap) = G->Trim(nodes.data(), nodes.data() + nodes.size(), 1787 &InverseMap); 1788 1789 // Create owning pointers for GTrim and NMap just to ensure that they are 1790 // released when this function exists. 1791 OwningPtr<ExplodedGraph> AutoReleaseGTrim(GTrim); 1792 OwningPtr<InterExplodedGraphMap> AutoReleaseNMap(NMap); 1793 1794 // Find the (first) error node in the trimmed graph. We just need to consult 1795 // the node map (NMap) which maps from nodes in the original graph to nodes 1796 // in the new graph. 1797 1798 std::queue<const ExplodedNode*> WS; 1799 typedef llvm::DenseMap<const ExplodedNode*, unsigned> IndexMapTy; 1800 IndexMapTy IndexMap; 1801 1802 for (unsigned nodeIndex = 0 ; nodeIndex < nodes.size(); ++nodeIndex) { 1803 const ExplodedNode *originalNode = nodes[nodeIndex]; 1804 if (const ExplodedNode *N = NMap->getMappedNode(originalNode)) { 1805 WS.push(N); 1806 IndexMap[originalNode] = nodeIndex; 1807 } 1808 } 1809 1810 assert(!WS.empty() && "No error node found in the trimmed graph."); 1811 1812 // Create a new (third!) graph with a single path. This is the graph 1813 // that will be returned to the caller. 1814 ExplodedGraph *GNew = new ExplodedGraph(); 1815 1816 // Sometimes the trimmed graph can contain a cycle. Perform a reverse BFS 1817 // to the root node, and then construct a new graph that contains only 1818 // a single path. 1819 llvm::DenseMap<const void*,unsigned> Visited; 1820 1821 unsigned cnt = 0; 1822 const ExplodedNode *Root = 0; 1823 1824 while (!WS.empty()) { 1825 const ExplodedNode *Node = WS.front(); 1826 WS.pop(); 1827 1828 if (Visited.find(Node) != Visited.end()) 1829 continue; 1830 1831 Visited[Node] = cnt++; 1832 1833 if (Node->pred_empty()) { 1834 Root = Node; 1835 break; 1836 } 1837 1838 for (ExplodedNode::const_pred_iterator I=Node->pred_begin(), 1839 E=Node->pred_end(); I!=E; ++I) 1840 WS.push(*I); 1841 } 1842 1843 assert(Root); 1844 1845 // Now walk from the root down the BFS path, always taking the successor 1846 // with the lowest number. 1847 ExplodedNode *Last = 0, *First = 0; 1848 NodeBackMap *BM = new NodeBackMap(); 1849 unsigned NodeIndex = 0; 1850 1851 for ( const ExplodedNode *N = Root ;;) { 1852 // Lookup the number associated with the current node. 1853 llvm::DenseMap<const void*,unsigned>::iterator I = Visited.find(N); 1854 assert(I != Visited.end()); 1855 1856 // Create the equivalent node in the new graph with the same state 1857 // and location. 1858 ExplodedNode *NewN = GNew->getNode(N->getLocation(), N->getState()); 1859 1860 // Store the mapping to the original node. 1861 llvm::DenseMap<const void*, const void*>::iterator IMitr=InverseMap.find(N); 1862 assert(IMitr != InverseMap.end() && "No mapping to original node."); 1863 (*BM)[NewN] = (const ExplodedNode*) IMitr->second; 1864 1865 // Link up the new node with the previous node. 1866 if (Last) 1867 NewN->addPredecessor(Last, *GNew); 1868 1869 Last = NewN; 1870 1871 // Are we at the final node? 1872 IndexMapTy::iterator IMI = 1873 IndexMap.find((const ExplodedNode*)(IMitr->second)); 1874 if (IMI != IndexMap.end()) { 1875 First = NewN; 1876 NodeIndex = IMI->second; 1877 break; 1878 } 1879 1880 // Find the next successor node. We choose the node that is marked 1881 // with the lowest DFS number. 1882 ExplodedNode::const_succ_iterator SI = N->succ_begin(); 1883 ExplodedNode::const_succ_iterator SE = N->succ_end(); 1884 N = 0; 1885 1886 for (unsigned MinVal = 0; SI != SE; ++SI) { 1887 1888 I = Visited.find(*SI); 1889 1890 if (I == Visited.end()) 1891 continue; 1892 1893 if (!N || I->second < MinVal) { 1894 N = *SI; 1895 MinVal = I->second; 1896 } 1897 } 1898 1899 assert(N); 1900 } 1901 1902 assert(First); 1903 1904 return std::make_pair(std::make_pair(GNew, BM), 1905 std::make_pair(First, NodeIndex)); 1906} 1907 1908/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object 1909/// and collapses PathDiagosticPieces that are expanded by macros. 1910static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) { 1911 typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>, 1912 SourceLocation> > MacroStackTy; 1913 1914 typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> > 1915 PiecesTy; 1916 1917 MacroStackTy MacroStack; 1918 PiecesTy Pieces; 1919 1920 for (PathPieces::const_iterator I = path.begin(), E = path.end(); 1921 I!=E; ++I) { 1922 1923 PathDiagnosticPiece *piece = I->getPtr(); 1924 1925 // Recursively compact calls. 1926 if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){ 1927 CompactPathDiagnostic(call->path, SM); 1928 } 1929 1930 // Get the location of the PathDiagnosticPiece. 1931 const FullSourceLoc Loc = piece->getLocation().asLocation(); 1932 1933 // Determine the instantiation location, which is the location we group 1934 // related PathDiagnosticPieces. 1935 SourceLocation InstantiationLoc = Loc.isMacroID() ? 1936 SM.getExpansionLoc(Loc) : 1937 SourceLocation(); 1938 1939 if (Loc.isFileID()) { 1940 MacroStack.clear(); 1941 Pieces.push_back(piece); 1942 continue; 1943 } 1944 1945 assert(Loc.isMacroID()); 1946 1947 // Is the PathDiagnosticPiece within the same macro group? 1948 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) { 1949 MacroStack.back().first->subPieces.push_back(piece); 1950 continue; 1951 } 1952 1953 // We aren't in the same group. Are we descending into a new macro 1954 // or are part of an old one? 1955 IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup; 1956 1957 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ? 1958 SM.getExpansionLoc(Loc) : 1959 SourceLocation(); 1960 1961 // Walk the entire macro stack. 1962 while (!MacroStack.empty()) { 1963 if (InstantiationLoc == MacroStack.back().second) { 1964 MacroGroup = MacroStack.back().first; 1965 break; 1966 } 1967 1968 if (ParentInstantiationLoc == MacroStack.back().second) { 1969 MacroGroup = MacroStack.back().first; 1970 break; 1971 } 1972 1973 MacroStack.pop_back(); 1974 } 1975 1976 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) { 1977 // Create a new macro group and add it to the stack. 1978 PathDiagnosticMacroPiece *NewGroup = 1979 new PathDiagnosticMacroPiece( 1980 PathDiagnosticLocation::createSingleLocation(piece->getLocation())); 1981 1982 if (MacroGroup) 1983 MacroGroup->subPieces.push_back(NewGroup); 1984 else { 1985 assert(InstantiationLoc.isFileID()); 1986 Pieces.push_back(NewGroup); 1987 } 1988 1989 MacroGroup = NewGroup; 1990 MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc)); 1991 } 1992 1993 // Finally, add the PathDiagnosticPiece to the group. 1994 MacroGroup->subPieces.push_back(piece); 1995 } 1996 1997 // Now take the pieces and construct a new PathDiagnostic. 1998 path.clear(); 1999 2000 for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I) 2001 path.push_back(*I); 2002} 2003 2004bool GRBugReporter::generatePathDiagnostic(PathDiagnostic& PD, 2005 PathDiagnosticConsumer &PC, 2006 ArrayRef<BugReport *> &bugReports) { 2007 assert(!bugReports.empty()); 2008 2009 bool HasValid = false; 2010 SmallVector<const ExplodedNode *, 10> errorNodes; 2011 for (ArrayRef<BugReport*>::iterator I = bugReports.begin(), 2012 E = bugReports.end(); I != E; ++I) { 2013 if ((*I)->isValid()) { 2014 HasValid = true; 2015 errorNodes.push_back((*I)->getErrorNode()); 2016 } else { 2017 errorNodes.push_back(0); 2018 } 2019 } 2020 2021 // If all the reports have been marked invalid, we're done. 2022 if (!HasValid) 2023 return false; 2024 2025 // Construct a new graph that contains only a single path from the error 2026 // node to a root. 2027 const std::pair<std::pair<ExplodedGraph*, NodeBackMap*>, 2028 std::pair<ExplodedNode*, unsigned> >& 2029 GPair = MakeReportGraph(&getGraph(), errorNodes); 2030 2031 // Find the BugReport with the original location. 2032 assert(GPair.second.second < bugReports.size()); 2033 BugReport *R = bugReports[GPair.second.second]; 2034 assert(R && "No original report found for sliced graph."); 2035 assert(R->isValid() && "Report selected from trimmed graph marked invalid."); 2036 2037 OwningPtr<ExplodedGraph> ReportGraph(GPair.first.first); 2038 OwningPtr<NodeBackMap> BackMap(GPair.first.second); 2039 const ExplodedNode *N = GPair.second.first; 2040 2041 // Start building the path diagnostic... 2042 PathDiagnosticBuilder PDB(*this, R, BackMap.get(), &PC); 2043 2044 // Register additional node visitors. 2045 R->addVisitor(new NilReceiverBRVisitor()); 2046 R->addVisitor(new ConditionBRVisitor()); 2047 2048 BugReport::VisitorList visitors; 2049 unsigned originalReportConfigToken, finalReportConfigToken; 2050 2051 // While generating diagnostics, it's possible the visitors will decide 2052 // new symbols and regions are interesting, or add other visitors based on 2053 // the information they find. If they do, we need to regenerate the path 2054 // based on our new report configuration. 2055 do { 2056 // Get a clean copy of all the visitors. 2057 for (BugReport::visitor_iterator I = R->visitor_begin(), 2058 E = R->visitor_end(); I != E; ++I) 2059 visitors.push_back((*I)->clone()); 2060 2061 // Clear out the active path from any previous work. 2062 PD.resetPath(); 2063 originalReportConfigToken = R->getConfigurationChangeToken(); 2064 2065 // Generate the very last diagnostic piece - the piece is visible before 2066 // the trace is expanded. 2067 if (PDB.getGenerationScheme() != PathDiagnosticConsumer::None) { 2068 PathDiagnosticPiece *LastPiece = 0; 2069 for (BugReport::visitor_iterator I = visitors.begin(), E = visitors.end(); 2070 I != E; ++I) { 2071 if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) { 2072 assert (!LastPiece && 2073 "There can only be one final piece in a diagnostic."); 2074 LastPiece = Piece; 2075 } 2076 } 2077 if (!LastPiece) 2078 LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R); 2079 if (LastPiece) 2080 PD.setEndOfPath(LastPiece); 2081 else 2082 return false; 2083 } 2084 2085 switch (PDB.getGenerationScheme()) { 2086 case PathDiagnosticConsumer::Extensive: 2087 if (!GenerateExtensivePathDiagnostic(PD, PDB, N, visitors)) { 2088 assert(!R->isValid() && "Failed on valid report"); 2089 // Try again. We'll filter out the bad report when we trim the graph. 2090 // FIXME: It would be more efficient to use the same intermediate 2091 // trimmed graph, and just repeat the shortest-path search. 2092 return generatePathDiagnostic(PD, PC, bugReports); 2093 } 2094 break; 2095 case PathDiagnosticConsumer::Minimal: 2096 if (!GenerateMinimalPathDiagnostic(PD, PDB, N, visitors)) { 2097 assert(!R->isValid() && "Failed on valid report"); 2098 // Try again. We'll filter out the bad report when we trim the graph. 2099 return generatePathDiagnostic(PD, PC, bugReports); 2100 } 2101 break; 2102 case PathDiagnosticConsumer::None: 2103 if (!GenerateVisitorsOnlyPathDiagnostic(PD, PDB, N, visitors)) { 2104 assert(!R->isValid() && "Failed on valid report"); 2105 // Try again. We'll filter out the bad report when we trim the graph. 2106 return generatePathDiagnostic(PD, PC, bugReports); 2107 } 2108 break; 2109 } 2110 2111 // Clean up the visitors we used. 2112 llvm::DeleteContainerPointers(visitors); 2113 2114 // Did anything change while generating this path? 2115 finalReportConfigToken = R->getConfigurationChangeToken(); 2116 } while(finalReportConfigToken != originalReportConfigToken); 2117 2118 // Finally, prune the diagnostic path of uninteresting stuff. 2119 if (!PD.path.empty()) { 2120 // Remove messages that are basically the same. 2121 removeRedundantMsgs(PD.getMutablePieces()); 2122 2123 if (R->shouldPrunePath()) { 2124 bool hasSomethingInteresting = RemoveUnneededCalls(PD.getMutablePieces(), 2125 R); 2126 assert(hasSomethingInteresting); 2127 (void) hasSomethingInteresting; 2128 } 2129 2130 adjustCallLocations(PD.getMutablePieces()); 2131 } 2132 2133 return true; 2134} 2135 2136void BugReporter::Register(BugType *BT) { 2137 BugTypes = F.add(BugTypes, BT); 2138} 2139 2140bool BugReporter::suppressReport(BugReport *R) { 2141 const Stmt *S = R->getStmt(); 2142 if (!S) 2143 return false; 2144 2145 // Here we suppress false positives coming from system macros. This list is 2146 // based on known issues. 2147 2148 // Skip reports within the sys/queue.h macros as we do not have the ability to 2149 // reason about data structure shapes. 2150 SourceManager &SM = getSourceManager(); 2151 SourceLocation Loc = S->getLocStart(); 2152 while (Loc.isMacroID()) { 2153 if (SM.isInSystemMacro(Loc) && 2154 (SM.getFilename(SM.getSpellingLoc(Loc)).endswith("sys/queue.h"))) 2155 return true; 2156 Loc = SM.getSpellingLoc(Loc); 2157 } 2158 2159 return false; 2160} 2161 2162void BugReporter::emitReport(BugReport* R) { 2163 if (suppressReport(R)) 2164 return; 2165 2166 // Compute the bug report's hash to determine its equivalence class. 2167 llvm::FoldingSetNodeID ID; 2168 R->Profile(ID); 2169 2170 // Lookup the equivance class. If there isn't one, create it. 2171 BugType& BT = R->getBugType(); 2172 Register(&BT); 2173 void *InsertPos; 2174 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos); 2175 2176 if (!EQ) { 2177 EQ = new BugReportEquivClass(R); 2178 EQClasses.InsertNode(EQ, InsertPos); 2179 EQClassesVector.push_back(EQ); 2180 } 2181 else 2182 EQ->AddReport(R); 2183} 2184 2185 2186//===----------------------------------------------------------------------===// 2187// Emitting reports in equivalence classes. 2188//===----------------------------------------------------------------------===// 2189 2190namespace { 2191struct FRIEC_WLItem { 2192 const ExplodedNode *N; 2193 ExplodedNode::const_succ_iterator I, E; 2194 2195 FRIEC_WLItem(const ExplodedNode *n) 2196 : N(n), I(N->succ_begin()), E(N->succ_end()) {} 2197}; 2198} 2199 2200static BugReport * 2201FindReportInEquivalenceClass(BugReportEquivClass& EQ, 2202 SmallVectorImpl<BugReport*> &bugReports) { 2203 2204 BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end(); 2205 assert(I != E); 2206 BugType& BT = I->getBugType(); 2207 2208 // If we don't need to suppress any of the nodes because they are 2209 // post-dominated by a sink, simply add all the nodes in the equivalence class 2210 // to 'Nodes'. Any of the reports will serve as a "representative" report. 2211 if (!BT.isSuppressOnSink()) { 2212 BugReport *R = I; 2213 for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) { 2214 const ExplodedNode *N = I->getErrorNode(); 2215 if (N) { 2216 R = I; 2217 bugReports.push_back(R); 2218 } 2219 } 2220 return R; 2221 } 2222 2223 // For bug reports that should be suppressed when all paths are post-dominated 2224 // by a sink node, iterate through the reports in the equivalence class 2225 // until we find one that isn't post-dominated (if one exists). We use a 2226 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write 2227 // this as a recursive function, but we don't want to risk blowing out the 2228 // stack for very long paths. 2229 BugReport *exampleReport = 0; 2230 2231 for (; I != E; ++I) { 2232 const ExplodedNode *errorNode = I->getErrorNode(); 2233 2234 if (!errorNode) 2235 continue; 2236 if (errorNode->isSink()) { 2237 llvm_unreachable( 2238 "BugType::isSuppressSink() should not be 'true' for sink end nodes"); 2239 } 2240 // No successors? By definition this nodes isn't post-dominated by a sink. 2241 if (errorNode->succ_empty()) { 2242 bugReports.push_back(I); 2243 if (!exampleReport) 2244 exampleReport = I; 2245 continue; 2246 } 2247 2248 // At this point we know that 'N' is not a sink and it has at least one 2249 // successor. Use a DFS worklist to find a non-sink end-of-path node. 2250 typedef FRIEC_WLItem WLItem; 2251 typedef SmallVector<WLItem, 10> DFSWorkList; 2252 llvm::DenseMap<const ExplodedNode *, unsigned> Visited; 2253 2254 DFSWorkList WL; 2255 WL.push_back(errorNode); 2256 Visited[errorNode] = 1; 2257 2258 while (!WL.empty()) { 2259 WLItem &WI = WL.back(); 2260 assert(!WI.N->succ_empty()); 2261 2262 for (; WI.I != WI.E; ++WI.I) { 2263 const ExplodedNode *Succ = *WI.I; 2264 // End-of-path node? 2265 if (Succ->succ_empty()) { 2266 // If we found an end-of-path node that is not a sink. 2267 if (!Succ->isSink()) { 2268 bugReports.push_back(I); 2269 if (!exampleReport) 2270 exampleReport = I; 2271 WL.clear(); 2272 break; 2273 } 2274 // Found a sink? Continue on to the next successor. 2275 continue; 2276 } 2277 // Mark the successor as visited. If it hasn't been explored, 2278 // enqueue it to the DFS worklist. 2279 unsigned &mark = Visited[Succ]; 2280 if (!mark) { 2281 mark = 1; 2282 WL.push_back(Succ); 2283 break; 2284 } 2285 } 2286 2287 // The worklist may have been cleared at this point. First 2288 // check if it is empty before checking the last item. 2289 if (!WL.empty() && &WL.back() == &WI) 2290 WL.pop_back(); 2291 } 2292 } 2293 2294 // ExampleReport will be NULL if all the nodes in the equivalence class 2295 // were post-dominated by sinks. 2296 return exampleReport; 2297} 2298 2299void BugReporter::FlushReport(BugReportEquivClass& EQ) { 2300 SmallVector<BugReport*, 10> bugReports; 2301 BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports); 2302 if (exampleReport) { 2303 const PathDiagnosticConsumers &C = getPathDiagnosticConsumers(); 2304 for (PathDiagnosticConsumers::const_iterator I=C.begin(), 2305 E=C.end(); I != E; ++I) { 2306 FlushReport(exampleReport, **I, bugReports); 2307 } 2308 } 2309} 2310 2311void BugReporter::FlushReport(BugReport *exampleReport, 2312 PathDiagnosticConsumer &PD, 2313 ArrayRef<BugReport*> bugReports) { 2314 2315 // FIXME: Make sure we use the 'R' for the path that was actually used. 2316 // Probably doesn't make a difference in practice. 2317 BugType& BT = exampleReport->getBugType(); 2318 2319 OwningPtr<PathDiagnostic> 2320 D(new PathDiagnostic(exampleReport->getDeclWithIssue(), 2321 exampleReport->getBugType().getName(), 2322 exampleReport->getDescription(), 2323 exampleReport->getShortDescription(/*Fallback=*/false), 2324 BT.getCategory(), 2325 exampleReport->getUniqueingLocation(), 2326 exampleReport->getUniqueingDecl())); 2327 2328 // Generate the full path diagnostic, using the generation scheme 2329 // specified by the PathDiagnosticConsumer. Note that we have to generate 2330 // path diagnostics even for consumers which do not support paths, because 2331 // the BugReporterVisitors may mark this bug as a false positive. 2332 if (!bugReports.empty()) 2333 if (!generatePathDiagnostic(*D.get(), PD, bugReports)) 2334 return; 2335 2336 // If the path is empty, generate a single step path with the location 2337 // of the issue. 2338 if (D->path.empty()) { 2339 PathDiagnosticLocation L = exampleReport->getLocation(getSourceManager()); 2340 PathDiagnosticPiece *piece = 2341 new PathDiagnosticEventPiece(L, exampleReport->getDescription()); 2342 BugReport::ranges_iterator Beg, End; 2343 llvm::tie(Beg, End) = exampleReport->getRanges(); 2344 for ( ; Beg != End; ++Beg) 2345 piece->addRange(*Beg); 2346 D->setEndOfPath(piece); 2347 } 2348 2349 // Get the meta data. 2350 const BugReport::ExtraTextList &Meta = exampleReport->getExtraText(); 2351 for (BugReport::ExtraTextList::const_iterator i = Meta.begin(), 2352 e = Meta.end(); i != e; ++i) { 2353 D->addMeta(*i); 2354 } 2355 2356 PD.HandlePathDiagnostic(D.take()); 2357} 2358 2359void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, 2360 StringRef name, 2361 StringRef category, 2362 StringRef str, PathDiagnosticLocation Loc, 2363 SourceRange* RBeg, unsigned NumRanges) { 2364 2365 // 'BT' is owned by BugReporter. 2366 BugType *BT = getBugTypeForName(name, category); 2367 BugReport *R = new BugReport(*BT, str, Loc); 2368 R->setDeclWithIssue(DeclWithIssue); 2369 for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg); 2370 emitReport(R); 2371} 2372 2373BugType *BugReporter::getBugTypeForName(StringRef name, 2374 StringRef category) { 2375 SmallString<136> fullDesc; 2376 llvm::raw_svector_ostream(fullDesc) << name << ":" << category; 2377 llvm::StringMapEntry<BugType *> & 2378 entry = StrBugTypes.GetOrCreateValue(fullDesc); 2379 BugType *BT = entry.getValue(); 2380 if (!BT) { 2381 BT = new BugType(name, category); 2382 entry.setValue(BT); 2383 } 2384 return BT; 2385} 2386