BugReporter.cpp revision e86ee1a213d244bb66b7eef3e9ab2266908cf4af
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/// Recursively scan through a path and make sure that all call pieces have 214/// valid locations. Note that all other pieces with invalid locations should 215/// have already been pruned out. 216static void adjustCallLocations(PathPieces &Pieces, 217 PathDiagnosticLocation *LastCallLocation = 0) { 218 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E; ++I) { 219 PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I); 220 221 if (!Call) { 222 assert((*I)->getLocation().asLocation().isValid()); 223 continue; 224 } 225 226 if (LastCallLocation) { 227 if (!Call->callEnter.asLocation().isValid() || 228 Call->getCaller()->isImplicit()) 229 Call->callEnter = *LastCallLocation; 230 if (!Call->callReturn.asLocation().isValid() || 231 Call->getCaller()->isImplicit()) 232 Call->callReturn = *LastCallLocation; 233 } 234 235 // Recursively clean out the subclass. Keep this call around if 236 // it contains any informative diagnostics. 237 PathDiagnosticLocation *ThisCallLocation; 238 if (Call->callEnterWithin.asLocation().isValid() && 239 !Call->getCallee()->isImplicit()) 240 ThisCallLocation = &Call->callEnterWithin; 241 else 242 ThisCallLocation = &Call->callEnter; 243 244 assert(ThisCallLocation && "Outermost call has an invalid location"); 245 adjustCallLocations(Call->path, ThisCallLocation); 246 } 247} 248 249//===----------------------------------------------------------------------===// 250// PathDiagnosticBuilder and its associated routines and helper objects. 251//===----------------------------------------------------------------------===// 252 253namespace { 254class NodeMapClosure : public BugReport::NodeResolver { 255 InterExplodedGraphMap &M; 256public: 257 NodeMapClosure(InterExplodedGraphMap &m) : M(m) {} 258 259 const ExplodedNode *getOriginalNode(const ExplodedNode *N) { 260 return M.lookup(N); 261 } 262}; 263 264class PathDiagnosticBuilder : public BugReporterContext { 265 BugReport *R; 266 PathDiagnosticConsumer *PDC; 267 NodeMapClosure NMC; 268public: 269 const LocationContext *LC; 270 271 PathDiagnosticBuilder(GRBugReporter &br, 272 BugReport *r, InterExplodedGraphMap &Backmap, 273 PathDiagnosticConsumer *pdc) 274 : BugReporterContext(br), 275 R(r), PDC(pdc), NMC(Backmap), LC(r->getErrorNode()->getLocationContext()) 276 {} 277 278 PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N); 279 280 PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os, 281 const ExplodedNode *N); 282 283 BugReport *getBugReport() { return R; } 284 285 Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); } 286 287 ParentMap& getParentMap() { return LC->getParentMap(); } 288 289 const Stmt *getParent(const Stmt *S) { 290 return getParentMap().getParent(S); 291 } 292 293 virtual NodeMapClosure& getNodeResolver() { return NMC; } 294 295 PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S); 296 297 PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const { 298 return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Extensive; 299 } 300 301 bool supportsLogicalOpControlFlow() const { 302 return PDC ? PDC->supportsLogicalOpControlFlow() : true; 303 } 304}; 305} // end anonymous namespace 306 307PathDiagnosticLocation 308PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) { 309 if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N)) 310 return PathDiagnosticLocation(S, getSourceManager(), LC); 311 312 return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(), 313 getSourceManager()); 314} 315 316PathDiagnosticLocation 317PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os, 318 const ExplodedNode *N) { 319 320 // Slow, but probably doesn't matter. 321 if (os.str().empty()) 322 os << ' '; 323 324 const PathDiagnosticLocation &Loc = ExecutionContinues(N); 325 326 if (Loc.asStmt()) 327 os << "Execution continues on line " 328 << getSourceManager().getExpansionLineNumber(Loc.asLocation()) 329 << '.'; 330 else { 331 os << "Execution jumps to the end of the "; 332 const Decl *D = N->getLocationContext()->getDecl(); 333 if (isa<ObjCMethodDecl>(D)) 334 os << "method"; 335 else if (isa<FunctionDecl>(D)) 336 os << "function"; 337 else { 338 assert(isa<BlockDecl>(D)); 339 os << "anonymous block"; 340 } 341 os << '.'; 342 } 343 344 return Loc; 345} 346 347static bool IsNested(const Stmt *S, ParentMap &PM) { 348 if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S))) 349 return true; 350 351 const Stmt *Parent = PM.getParentIgnoreParens(S); 352 353 if (Parent) 354 switch (Parent->getStmtClass()) { 355 case Stmt::ForStmtClass: 356 case Stmt::DoStmtClass: 357 case Stmt::WhileStmtClass: 358 return true; 359 default: 360 break; 361 } 362 363 return false; 364} 365 366PathDiagnosticLocation 367PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) { 368 assert(S && "Null Stmt *passed to getEnclosingStmtLocation"); 369 ParentMap &P = getParentMap(); 370 SourceManager &SMgr = getSourceManager(); 371 372 while (IsNested(S, P)) { 373 const Stmt *Parent = P.getParentIgnoreParens(S); 374 375 if (!Parent) 376 break; 377 378 switch (Parent->getStmtClass()) { 379 case Stmt::BinaryOperatorClass: { 380 const BinaryOperator *B = cast<BinaryOperator>(Parent); 381 if (B->isLogicalOp()) 382 return PathDiagnosticLocation(S, SMgr, LC); 383 break; 384 } 385 case Stmt::CompoundStmtClass: 386 case Stmt::StmtExprClass: 387 return PathDiagnosticLocation(S, SMgr, LC); 388 case Stmt::ChooseExprClass: 389 // Similar to '?' if we are referring to condition, just have the edge 390 // point to the entire choose expression. 391 if (cast<ChooseExpr>(Parent)->getCond() == S) 392 return PathDiagnosticLocation(Parent, SMgr, LC); 393 else 394 return PathDiagnosticLocation(S, SMgr, LC); 395 case Stmt::BinaryConditionalOperatorClass: 396 case Stmt::ConditionalOperatorClass: 397 // For '?', if we are referring to condition, just have the edge point 398 // to the entire '?' expression. 399 if (cast<AbstractConditionalOperator>(Parent)->getCond() == S) 400 return PathDiagnosticLocation(Parent, SMgr, LC); 401 else 402 return PathDiagnosticLocation(S, SMgr, LC); 403 case Stmt::DoStmtClass: 404 return PathDiagnosticLocation(S, SMgr, LC); 405 case Stmt::ForStmtClass: 406 if (cast<ForStmt>(Parent)->getBody() == S) 407 return PathDiagnosticLocation(S, SMgr, LC); 408 break; 409 case Stmt::IfStmtClass: 410 if (cast<IfStmt>(Parent)->getCond() != S) 411 return PathDiagnosticLocation(S, SMgr, LC); 412 break; 413 case Stmt::ObjCForCollectionStmtClass: 414 if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S) 415 return PathDiagnosticLocation(S, SMgr, LC); 416 break; 417 case Stmt::WhileStmtClass: 418 if (cast<WhileStmt>(Parent)->getCond() != S) 419 return PathDiagnosticLocation(S, SMgr, LC); 420 break; 421 default: 422 break; 423 } 424 425 S = Parent; 426 } 427 428 assert(S && "Cannot have null Stmt for PathDiagnosticLocation"); 429 430 // Special case: DeclStmts can appear in for statement declarations, in which 431 // case the ForStmt is the context. 432 if (isa<DeclStmt>(S)) { 433 if (const Stmt *Parent = P.getParent(S)) { 434 switch (Parent->getStmtClass()) { 435 case Stmt::ForStmtClass: 436 case Stmt::ObjCForCollectionStmtClass: 437 return PathDiagnosticLocation(Parent, SMgr, LC); 438 default: 439 break; 440 } 441 } 442 } 443 else if (isa<BinaryOperator>(S)) { 444 // Special case: the binary operator represents the initialization 445 // code in a for statement (this can happen when the variable being 446 // initialized is an old variable. 447 if (const ForStmt *FS = 448 dyn_cast_or_null<ForStmt>(P.getParentIgnoreParens(S))) { 449 if (FS->getInit() == S) 450 return PathDiagnosticLocation(FS, SMgr, LC); 451 } 452 } 453 454 return PathDiagnosticLocation(S, SMgr, LC); 455} 456 457//===----------------------------------------------------------------------===// 458// "Visitors only" path diagnostic generation algorithm. 459//===----------------------------------------------------------------------===// 460static bool GenerateVisitorsOnlyPathDiagnostic(PathDiagnostic &PD, 461 PathDiagnosticBuilder &PDB, 462 const ExplodedNode *N, 463 ArrayRef<BugReporterVisitor *> visitors) { 464 // All path generation skips the very first node (the error node). 465 // This is because there is special handling for the end-of-path note. 466 N = N->getFirstPred(); 467 if (!N) 468 return true; 469 470 BugReport *R = PDB.getBugReport(); 471 while (const ExplodedNode *Pred = N->getFirstPred()) { 472 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 473 E = visitors.end(); 474 I != E; ++I) { 475 // Visit all the node pairs, but throw the path pieces away. 476 PathDiagnosticPiece *Piece = (*I)->VisitNode(N, Pred, PDB, *R); 477 delete Piece; 478 } 479 480 N = Pred; 481 } 482 483 return R->isValid(); 484} 485 486//===----------------------------------------------------------------------===// 487// "Minimal" path diagnostic generation algorithm. 488//===----------------------------------------------------------------------===// 489typedef std::pair<PathDiagnosticCallPiece*, const ExplodedNode*> StackDiagPair; 490typedef SmallVector<StackDiagPair, 6> StackDiagVector; 491 492static void updateStackPiecesWithMessage(PathDiagnosticPiece *P, 493 StackDiagVector &CallStack) { 494 // If the piece contains a special message, add it to all the call 495 // pieces on the active stack. 496 if (PathDiagnosticEventPiece *ep = 497 dyn_cast<PathDiagnosticEventPiece>(P)) { 498 499 if (ep->hasCallStackHint()) 500 for (StackDiagVector::iterator I = CallStack.begin(), 501 E = CallStack.end(); I != E; ++I) { 502 PathDiagnosticCallPiece *CP = I->first; 503 const ExplodedNode *N = I->second; 504 std::string stackMsg = ep->getCallStackMessage(N); 505 506 // The last message on the path to final bug is the most important 507 // one. Since we traverse the path backwards, do not add the message 508 // if one has been previously added. 509 if (!CP->hasCallStackMessage()) 510 CP->setCallStackMessage(stackMsg); 511 } 512 } 513} 514 515static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM); 516 517static bool GenerateMinimalPathDiagnostic(PathDiagnostic& PD, 518 PathDiagnosticBuilder &PDB, 519 const ExplodedNode *N, 520 LocationContextMap &LCM, 521 ArrayRef<BugReporterVisitor *> visitors) { 522 523 SourceManager& SMgr = PDB.getSourceManager(); 524 const LocationContext *LC = PDB.LC; 525 const ExplodedNode *NextNode = N->pred_empty() 526 ? NULL : *(N->pred_begin()); 527 528 StackDiagVector CallStack; 529 530 while (NextNode) { 531 N = NextNode; 532 PDB.LC = N->getLocationContext(); 533 NextNode = N->getFirstPred(); 534 535 ProgramPoint P = N->getLocation(); 536 537 do { 538 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 539 PathDiagnosticCallPiece *C = 540 PathDiagnosticCallPiece::construct(N, *CE, SMgr); 541 // Record the mapping from call piece to LocationContext. 542 LCM[&C->path] = CE->getCalleeContext(); 543 PD.getActivePath().push_front(C); 544 PD.pushActivePath(&C->path); 545 CallStack.push_back(StackDiagPair(C, N)); 546 break; 547 } 548 549 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 550 // Flush all locations, and pop the active path. 551 bool VisitedEntireCall = PD.isWithinCall(); 552 PD.popActivePath(); 553 554 // Either we just added a bunch of stuff to the top-level path, or 555 // we have a previous CallExitEnd. If the former, it means that the 556 // path terminated within a function call. We must then take the 557 // current contents of the active path and place it within 558 // a new PathDiagnosticCallPiece. 559 PathDiagnosticCallPiece *C; 560 if (VisitedEntireCall) { 561 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 562 } else { 563 const Decl *Caller = CE->getLocationContext()->getDecl(); 564 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 565 // Record the mapping from call piece to LocationContext. 566 LCM[&C->path] = CE->getCalleeContext(); 567 } 568 569 C->setCallee(*CE, SMgr); 570 if (!CallStack.empty()) { 571 assert(CallStack.back().first == C); 572 CallStack.pop_back(); 573 } 574 break; 575 } 576 577 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 578 const CFGBlock *Src = BE->getSrc(); 579 const CFGBlock *Dst = BE->getDst(); 580 const Stmt *T = Src->getTerminator(); 581 582 if (!T) 583 break; 584 585 PathDiagnosticLocation Start = 586 PathDiagnosticLocation::createBegin(T, SMgr, 587 N->getLocationContext()); 588 589 switch (T->getStmtClass()) { 590 default: 591 break; 592 593 case Stmt::GotoStmtClass: 594 case Stmt::IndirectGotoStmtClass: { 595 const Stmt *S = PathDiagnosticLocation::getNextStmt(N); 596 597 if (!S) 598 break; 599 600 std::string sbuf; 601 llvm::raw_string_ostream os(sbuf); 602 const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S); 603 604 os << "Control jumps to line " 605 << End.asLocation().getExpansionLineNumber(); 606 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 607 Start, End, os.str())); 608 break; 609 } 610 611 case Stmt::SwitchStmtClass: { 612 // Figure out what case arm we took. 613 std::string sbuf; 614 llvm::raw_string_ostream os(sbuf); 615 616 if (const Stmt *S = Dst->getLabel()) { 617 PathDiagnosticLocation End(S, SMgr, LC); 618 619 switch (S->getStmtClass()) { 620 default: 621 os << "No cases match in the switch statement. " 622 "Control jumps to line " 623 << End.asLocation().getExpansionLineNumber(); 624 break; 625 case Stmt::DefaultStmtClass: 626 os << "Control jumps to the 'default' case at line " 627 << End.asLocation().getExpansionLineNumber(); 628 break; 629 630 case Stmt::CaseStmtClass: { 631 os << "Control jumps to 'case "; 632 const CaseStmt *Case = cast<CaseStmt>(S); 633 const Expr *LHS = Case->getLHS()->IgnoreParenCasts(); 634 635 // Determine if it is an enum. 636 bool GetRawInt = true; 637 638 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS)) { 639 // FIXME: Maybe this should be an assertion. Are there cases 640 // were it is not an EnumConstantDecl? 641 const EnumConstantDecl *D = 642 dyn_cast<EnumConstantDecl>(DR->getDecl()); 643 644 if (D) { 645 GetRawInt = false; 646 os << *D; 647 } 648 } 649 650 if (GetRawInt) 651 os << LHS->EvaluateKnownConstInt(PDB.getASTContext()); 652 653 os << ":' at line " 654 << End.asLocation().getExpansionLineNumber(); 655 break; 656 } 657 } 658 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 659 Start, End, os.str())); 660 } 661 else { 662 os << "'Default' branch taken. "; 663 const PathDiagnosticLocation &End = PDB.ExecutionContinues(os, N); 664 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 665 Start, End, os.str())); 666 } 667 668 break; 669 } 670 671 case Stmt::BreakStmtClass: 672 case Stmt::ContinueStmtClass: { 673 std::string sbuf; 674 llvm::raw_string_ostream os(sbuf); 675 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 676 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 677 Start, End, os.str())); 678 break; 679 } 680 681 // Determine control-flow for ternary '?'. 682 case Stmt::BinaryConditionalOperatorClass: 683 case Stmt::ConditionalOperatorClass: { 684 std::string sbuf; 685 llvm::raw_string_ostream os(sbuf); 686 os << "'?' condition is "; 687 688 if (*(Src->succ_begin()+1) == Dst) 689 os << "false"; 690 else 691 os << "true"; 692 693 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 694 695 if (const Stmt *S = End.asStmt()) 696 End = PDB.getEnclosingStmtLocation(S); 697 698 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 699 Start, End, os.str())); 700 break; 701 } 702 703 // Determine control-flow for short-circuited '&&' and '||'. 704 case Stmt::BinaryOperatorClass: { 705 if (!PDB.supportsLogicalOpControlFlow()) 706 break; 707 708 const BinaryOperator *B = cast<BinaryOperator>(T); 709 std::string sbuf; 710 llvm::raw_string_ostream os(sbuf); 711 os << "Left side of '"; 712 713 if (B->getOpcode() == BO_LAnd) { 714 os << "&&" << "' is "; 715 716 if (*(Src->succ_begin()+1) == Dst) { 717 os << "false"; 718 PathDiagnosticLocation End(B->getLHS(), SMgr, LC); 719 PathDiagnosticLocation Start = 720 PathDiagnosticLocation::createOperatorLoc(B, SMgr); 721 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 722 Start, End, os.str())); 723 } 724 else { 725 os << "true"; 726 PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); 727 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 728 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 729 Start, End, os.str())); 730 } 731 } 732 else { 733 assert(B->getOpcode() == BO_LOr); 734 os << "||" << "' is "; 735 736 if (*(Src->succ_begin()+1) == Dst) { 737 os << "false"; 738 PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); 739 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 740 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 741 Start, End, os.str())); 742 } 743 else { 744 os << "true"; 745 PathDiagnosticLocation End(B->getLHS(), SMgr, LC); 746 PathDiagnosticLocation Start = 747 PathDiagnosticLocation::createOperatorLoc(B, SMgr); 748 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 749 Start, End, os.str())); 750 } 751 } 752 753 break; 754 } 755 756 case Stmt::DoStmtClass: { 757 if (*(Src->succ_begin()) == Dst) { 758 std::string sbuf; 759 llvm::raw_string_ostream os(sbuf); 760 761 os << "Loop condition is true. "; 762 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 763 764 if (const Stmt *S = End.asStmt()) 765 End = PDB.getEnclosingStmtLocation(S); 766 767 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 768 Start, End, os.str())); 769 } 770 else { 771 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 772 773 if (const Stmt *S = End.asStmt()) 774 End = PDB.getEnclosingStmtLocation(S); 775 776 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 777 Start, End, "Loop condition is false. Exiting loop")); 778 } 779 780 break; 781 } 782 783 case Stmt::WhileStmtClass: 784 case Stmt::ForStmtClass: { 785 if (*(Src->succ_begin()+1) == Dst) { 786 std::string sbuf; 787 llvm::raw_string_ostream os(sbuf); 788 789 os << "Loop condition is false. "; 790 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 791 if (const Stmt *S = End.asStmt()) 792 End = PDB.getEnclosingStmtLocation(S); 793 794 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 795 Start, End, os.str())); 796 } 797 else { 798 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 799 if (const Stmt *S = End.asStmt()) 800 End = PDB.getEnclosingStmtLocation(S); 801 802 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 803 Start, End, "Loop condition is true. Entering loop body")); 804 } 805 806 break; 807 } 808 809 case Stmt::IfStmtClass: { 810 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 811 812 if (const Stmt *S = End.asStmt()) 813 End = PDB.getEnclosingStmtLocation(S); 814 815 if (*(Src->succ_begin()+1) == Dst) 816 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 817 Start, End, "Taking false branch")); 818 else 819 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 820 Start, End, "Taking true branch")); 821 822 break; 823 } 824 } 825 } 826 } while(0); 827 828 if (NextNode) { 829 // Add diagnostic pieces from custom visitors. 830 BugReport *R = PDB.getBugReport(); 831 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 832 E = visitors.end(); 833 I != E; ++I) { 834 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 835 PD.getActivePath().push_front(p); 836 updateStackPiecesWithMessage(p, CallStack); 837 } 838 } 839 } 840 } 841 842 if (!PDB.getBugReport()->isValid()) 843 return false; 844 845 // After constructing the full PathDiagnostic, do a pass over it to compact 846 // PathDiagnosticPieces that occur within a macro. 847 CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager()); 848 return true; 849} 850 851//===----------------------------------------------------------------------===// 852// "Extensive" PathDiagnostic generation. 853//===----------------------------------------------------------------------===// 854 855static bool IsControlFlowExpr(const Stmt *S) { 856 const Expr *E = dyn_cast<Expr>(S); 857 858 if (!E) 859 return false; 860 861 E = E->IgnoreParenCasts(); 862 863 if (isa<AbstractConditionalOperator>(E)) 864 return true; 865 866 if (const BinaryOperator *B = dyn_cast<BinaryOperator>(E)) 867 if (B->isLogicalOp()) 868 return true; 869 870 return false; 871} 872 873namespace { 874class ContextLocation : public PathDiagnosticLocation { 875 bool IsDead; 876public: 877 ContextLocation(const PathDiagnosticLocation &L, bool isdead = false) 878 : PathDiagnosticLocation(L), IsDead(isdead) {} 879 880 void markDead() { IsDead = true; } 881 bool isDead() const { return IsDead; } 882}; 883 884static PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L, 885 const LocationContext *LC, 886 bool firstCharOnly = false) { 887 if (const Stmt *S = L.asStmt()) { 888 const Stmt *Original = S; 889 while (1) { 890 // Adjust the location for some expressions that are best referenced 891 // by one of their subexpressions. 892 switch (S->getStmtClass()) { 893 default: 894 break; 895 case Stmt::ParenExprClass: 896 case Stmt::GenericSelectionExprClass: 897 S = cast<Expr>(S)->IgnoreParens(); 898 firstCharOnly = true; 899 continue; 900 case Stmt::BinaryConditionalOperatorClass: 901 case Stmt::ConditionalOperatorClass: 902 S = cast<AbstractConditionalOperator>(S)->getCond(); 903 firstCharOnly = true; 904 continue; 905 case Stmt::ChooseExprClass: 906 S = cast<ChooseExpr>(S)->getCond(); 907 firstCharOnly = true; 908 continue; 909 case Stmt::BinaryOperatorClass: 910 S = cast<BinaryOperator>(S)->getLHS(); 911 firstCharOnly = true; 912 continue; 913 } 914 915 break; 916 } 917 918 if (S != Original) 919 L = PathDiagnosticLocation(S, L.getManager(), LC); 920 } 921 922 if (firstCharOnly) 923 L = PathDiagnosticLocation::createSingleLocation(L); 924 925 return L; 926} 927 928class EdgeBuilder { 929 std::vector<ContextLocation> CLocs; 930 typedef std::vector<ContextLocation>::iterator iterator; 931 PathDiagnostic &PD; 932 PathDiagnosticBuilder &PDB; 933 PathDiagnosticLocation PrevLoc; 934 935 bool IsConsumedExpr(const PathDiagnosticLocation &L); 936 937 bool containsLocation(const PathDiagnosticLocation &Container, 938 const PathDiagnosticLocation &Containee); 939 940 PathDiagnosticLocation getContextLocation(const PathDiagnosticLocation &L); 941 942 943 944 void popLocation() { 945 if (!CLocs.back().isDead() && CLocs.back().asLocation().isFileID()) { 946 // For contexts, we only one the first character as the range. 947 rawAddEdge(cleanUpLocation(CLocs.back(), PDB.LC, true)); 948 } 949 CLocs.pop_back(); 950 } 951 952public: 953 EdgeBuilder(PathDiagnostic &pd, PathDiagnosticBuilder &pdb) 954 : PD(pd), PDB(pdb) { 955 956 // If the PathDiagnostic already has pieces, add the enclosing statement 957 // of the first piece as a context as well. 958 if (!PD.path.empty()) { 959 PrevLoc = (*PD.path.begin())->getLocation(); 960 961 if (const Stmt *S = PrevLoc.asStmt()) 962 addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 963 } 964 } 965 966 ~EdgeBuilder() { 967 while (!CLocs.empty()) popLocation(); 968 969 // Finally, add an initial edge from the start location of the first 970 // statement (if it doesn't already exist). 971 PathDiagnosticLocation L = PathDiagnosticLocation::createDeclBegin( 972 PDB.LC, 973 PDB.getSourceManager()); 974 if (L.isValid()) 975 rawAddEdge(L); 976 } 977 978 void flushLocations() { 979 while (!CLocs.empty()) 980 popLocation(); 981 PrevLoc = PathDiagnosticLocation(); 982 } 983 984 void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false, 985 bool IsPostJump = false); 986 987 void rawAddEdge(PathDiagnosticLocation NewLoc); 988 989 void addContext(const Stmt *S); 990 void addContext(const PathDiagnosticLocation &L); 991 void addExtendedContext(const Stmt *S); 992}; 993} // end anonymous namespace 994 995 996PathDiagnosticLocation 997EdgeBuilder::getContextLocation(const PathDiagnosticLocation &L) { 998 if (const Stmt *S = L.asStmt()) { 999 if (IsControlFlowExpr(S)) 1000 return L; 1001 1002 return PDB.getEnclosingStmtLocation(S); 1003 } 1004 1005 return L; 1006} 1007 1008bool EdgeBuilder::containsLocation(const PathDiagnosticLocation &Container, 1009 const PathDiagnosticLocation &Containee) { 1010 1011 if (Container == Containee) 1012 return true; 1013 1014 if (Container.asDecl()) 1015 return true; 1016 1017 if (const Stmt *S = Containee.asStmt()) 1018 if (const Stmt *ContainerS = Container.asStmt()) { 1019 while (S) { 1020 if (S == ContainerS) 1021 return true; 1022 S = PDB.getParent(S); 1023 } 1024 return false; 1025 } 1026 1027 // Less accurate: compare using source ranges. 1028 SourceRange ContainerR = Container.asRange(); 1029 SourceRange ContaineeR = Containee.asRange(); 1030 1031 SourceManager &SM = PDB.getSourceManager(); 1032 SourceLocation ContainerRBeg = SM.getExpansionLoc(ContainerR.getBegin()); 1033 SourceLocation ContainerREnd = SM.getExpansionLoc(ContainerR.getEnd()); 1034 SourceLocation ContaineeRBeg = SM.getExpansionLoc(ContaineeR.getBegin()); 1035 SourceLocation ContaineeREnd = SM.getExpansionLoc(ContaineeR.getEnd()); 1036 1037 unsigned ContainerBegLine = SM.getExpansionLineNumber(ContainerRBeg); 1038 unsigned ContainerEndLine = SM.getExpansionLineNumber(ContainerREnd); 1039 unsigned ContaineeBegLine = SM.getExpansionLineNumber(ContaineeRBeg); 1040 unsigned ContaineeEndLine = SM.getExpansionLineNumber(ContaineeREnd); 1041 1042 assert(ContainerBegLine <= ContainerEndLine); 1043 assert(ContaineeBegLine <= ContaineeEndLine); 1044 1045 return (ContainerBegLine <= ContaineeBegLine && 1046 ContainerEndLine >= ContaineeEndLine && 1047 (ContainerBegLine != ContaineeBegLine || 1048 SM.getExpansionColumnNumber(ContainerRBeg) <= 1049 SM.getExpansionColumnNumber(ContaineeRBeg)) && 1050 (ContainerEndLine != ContaineeEndLine || 1051 SM.getExpansionColumnNumber(ContainerREnd) >= 1052 SM.getExpansionColumnNumber(ContaineeREnd))); 1053} 1054 1055void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) { 1056 if (!PrevLoc.isValid()) { 1057 PrevLoc = NewLoc; 1058 return; 1059 } 1060 1061 const PathDiagnosticLocation &NewLocClean = cleanUpLocation(NewLoc, PDB.LC); 1062 const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc, PDB.LC); 1063 1064 if (PrevLocClean.asLocation().isInvalid()) { 1065 PrevLoc = NewLoc; 1066 return; 1067 } 1068 1069 if (NewLocClean.asLocation() == PrevLocClean.asLocation()) 1070 return; 1071 1072 // FIXME: Ignore intra-macro edges for now. 1073 if (NewLocClean.asLocation().getExpansionLoc() == 1074 PrevLocClean.asLocation().getExpansionLoc()) 1075 return; 1076 1077 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(NewLocClean, PrevLocClean)); 1078 PrevLoc = NewLoc; 1079} 1080 1081void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd, 1082 bool IsPostJump) { 1083 1084 if (!alwaysAdd && NewLoc.asLocation().isMacroID()) 1085 return; 1086 1087 const PathDiagnosticLocation &CLoc = getContextLocation(NewLoc); 1088 1089 while (!CLocs.empty()) { 1090 ContextLocation &TopContextLoc = CLocs.back(); 1091 1092 // Is the top location context the same as the one for the new location? 1093 if (TopContextLoc == CLoc) { 1094 if (alwaysAdd) { 1095 if (IsConsumedExpr(TopContextLoc)) 1096 TopContextLoc.markDead(); 1097 1098 rawAddEdge(NewLoc); 1099 } 1100 1101 if (IsPostJump) 1102 TopContextLoc.markDead(); 1103 return; 1104 } 1105 1106 if (containsLocation(TopContextLoc, CLoc)) { 1107 if (alwaysAdd) { 1108 rawAddEdge(NewLoc); 1109 1110 if (IsConsumedExpr(CLoc)) { 1111 CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/true)); 1112 return; 1113 } 1114 } 1115 1116 CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/IsPostJump)); 1117 return; 1118 } 1119 1120 // Context does not contain the location. Flush it. 1121 popLocation(); 1122 } 1123 1124 // If we reach here, there is no enclosing context. Just add the edge. 1125 rawAddEdge(NewLoc); 1126} 1127 1128bool EdgeBuilder::IsConsumedExpr(const PathDiagnosticLocation &L) { 1129 if (const Expr *X = dyn_cast_or_null<Expr>(L.asStmt())) 1130 return PDB.getParentMap().isConsumedExpr(X) && !IsControlFlowExpr(X); 1131 1132 return false; 1133} 1134 1135void EdgeBuilder::addExtendedContext(const Stmt *S) { 1136 if (!S) 1137 return; 1138 1139 const Stmt *Parent = PDB.getParent(S); 1140 while (Parent) { 1141 if (isa<CompoundStmt>(Parent)) 1142 Parent = PDB.getParent(Parent); 1143 else 1144 break; 1145 } 1146 1147 if (Parent) { 1148 switch (Parent->getStmtClass()) { 1149 case Stmt::DoStmtClass: 1150 case Stmt::ObjCAtSynchronizedStmtClass: 1151 addContext(Parent); 1152 default: 1153 break; 1154 } 1155 } 1156 1157 addContext(S); 1158} 1159 1160void EdgeBuilder::addContext(const Stmt *S) { 1161 if (!S) 1162 return; 1163 1164 PathDiagnosticLocation L(S, PDB.getSourceManager(), PDB.LC); 1165 addContext(L); 1166} 1167 1168void EdgeBuilder::addContext(const PathDiagnosticLocation &L) { 1169 while (!CLocs.empty()) { 1170 const PathDiagnosticLocation &TopContextLoc = CLocs.back(); 1171 1172 // Is the top location context the same as the one for the new location? 1173 if (TopContextLoc == L) 1174 return; 1175 1176 if (containsLocation(TopContextLoc, L)) { 1177 CLocs.push_back(L); 1178 return; 1179 } 1180 1181 // Context does not contain the location. Flush it. 1182 popLocation(); 1183 } 1184 1185 CLocs.push_back(L); 1186} 1187 1188// Cone-of-influence: support the reverse propagation of "interesting" symbols 1189// and values by tracing interesting calculations backwards through evaluated 1190// expressions along a path. This is probably overly complicated, but the idea 1191// is that if an expression computed an "interesting" value, the child 1192// expressions are are also likely to be "interesting" as well (which then 1193// propagates to the values they in turn compute). This reverse propagation 1194// is needed to track interesting correlations across function call boundaries, 1195// where formal arguments bind to actual arguments, etc. This is also needed 1196// because the constraint solver sometimes simplifies certain symbolic values 1197// into constants when appropriate, and this complicates reasoning about 1198// interesting values. 1199typedef llvm::DenseSet<const Expr *> InterestingExprs; 1200 1201static void reversePropagateIntererstingSymbols(BugReport &R, 1202 InterestingExprs &IE, 1203 const ProgramState *State, 1204 const Expr *Ex, 1205 const LocationContext *LCtx) { 1206 SVal V = State->getSVal(Ex, LCtx); 1207 if (!(R.isInteresting(V) || IE.count(Ex))) 1208 return; 1209 1210 switch (Ex->getStmtClass()) { 1211 default: 1212 if (!isa<CastExpr>(Ex)) 1213 break; 1214 // Fall through. 1215 case Stmt::BinaryOperatorClass: 1216 case Stmt::UnaryOperatorClass: { 1217 for (Stmt::const_child_iterator CI = Ex->child_begin(), 1218 CE = Ex->child_end(); 1219 CI != CE; ++CI) { 1220 if (const Expr *child = dyn_cast_or_null<Expr>(*CI)) { 1221 IE.insert(child); 1222 SVal ChildV = State->getSVal(child, LCtx); 1223 R.markInteresting(ChildV); 1224 } 1225 break; 1226 } 1227 } 1228 } 1229 1230 R.markInteresting(V); 1231} 1232 1233static void reversePropagateInterestingSymbols(BugReport &R, 1234 InterestingExprs &IE, 1235 const ProgramState *State, 1236 const LocationContext *CalleeCtx, 1237 const LocationContext *CallerCtx) 1238{ 1239 // FIXME: Handle non-CallExpr-based CallEvents. 1240 const StackFrameContext *Callee = CalleeCtx->getCurrentStackFrame(); 1241 const Stmt *CallSite = Callee->getCallSite(); 1242 if (const CallExpr *CE = dyn_cast_or_null<CallExpr>(CallSite)) { 1243 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CalleeCtx->getDecl())) { 1244 FunctionDecl::param_const_iterator PI = FD->param_begin(), 1245 PE = FD->param_end(); 1246 CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end(); 1247 for (; AI != AE && PI != PE; ++AI, ++PI) { 1248 if (const Expr *ArgE = *AI) { 1249 if (const ParmVarDecl *PD = *PI) { 1250 Loc LV = State->getLValue(PD, CalleeCtx); 1251 if (R.isInteresting(LV) || R.isInteresting(State->getRawSVal(LV))) 1252 IE.insert(ArgE); 1253 } 1254 } 1255 } 1256 } 1257 } 1258} 1259 1260//===----------------------------------------------------------------------===// 1261// Functions for determining if a loop was executed 0 times. 1262//===----------------------------------------------------------------------===// 1263 1264static bool isLoop(const Stmt *Term) { 1265 switch (Term->getStmtClass()) { 1266 case Stmt::ForStmtClass: 1267 case Stmt::WhileStmtClass: 1268 case Stmt::ObjCForCollectionStmtClass: 1269 return true; 1270 default: 1271 // Note that we intentionally do not include do..while here. 1272 return false; 1273 } 1274} 1275 1276static bool isJumpToFalseBranch(const BlockEdge *BE) { 1277 const CFGBlock *Src = BE->getSrc(); 1278 assert(Src->succ_size() == 2); 1279 return (*(Src->succ_begin()+1) == BE->getDst()); 1280} 1281 1282/// Return true if the terminator is a loop and the destination is the 1283/// false branch. 1284static bool isLoopJumpPastBody(const Stmt *Term, const BlockEdge *BE) { 1285 if (!isLoop(Term)) 1286 return false; 1287 1288 // Did we take the false branch? 1289 return isJumpToFalseBranch(BE); 1290} 1291 1292static bool isContainedByStmt(ParentMap &PM, const Stmt *S, const Stmt *SubS) { 1293 while (SubS) { 1294 if (SubS == S) 1295 return true; 1296 SubS = PM.getParent(SubS); 1297 } 1298 return false; 1299} 1300 1301static const Stmt *getStmtBeforeCond(ParentMap &PM, const Stmt *Term, 1302 const ExplodedNode *N) { 1303 while (N) { 1304 Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>(); 1305 if (SP) { 1306 const Stmt *S = SP->getStmt(); 1307 if (!isContainedByStmt(PM, Term, S)) 1308 return S; 1309 } 1310 N = N->getFirstPred(); 1311 } 1312 return 0; 1313} 1314 1315static bool isInLoopBody(ParentMap &PM, const Stmt *S, const Stmt *Term) { 1316 const Stmt *LoopBody = 0; 1317 switch (Term->getStmtClass()) { 1318 case Stmt::ForStmtClass: { 1319 const ForStmt *FS = cast<ForStmt>(Term); 1320 if (isContainedByStmt(PM, FS->getInc(), S)) 1321 return true; 1322 LoopBody = FS->getBody(); 1323 break; 1324 } 1325 case Stmt::ObjCForCollectionStmtClass: { 1326 const ObjCForCollectionStmt *FC = cast<ObjCForCollectionStmt>(Term); 1327 LoopBody = FC->getBody(); 1328 break; 1329 } 1330 case Stmt::WhileStmtClass: 1331 LoopBody = cast<WhileStmt>(Term)->getBody(); 1332 break; 1333 default: 1334 return false; 1335 } 1336 return isContainedByStmt(PM, LoopBody, S); 1337} 1338 1339//===----------------------------------------------------------------------===// 1340// Top-level logic for generating extensive path diagnostics. 1341//===----------------------------------------------------------------------===// 1342 1343static bool GenerateExtensivePathDiagnostic(PathDiagnostic& PD, 1344 PathDiagnosticBuilder &PDB, 1345 const ExplodedNode *N, 1346 LocationContextMap &LCM, 1347 ArrayRef<BugReporterVisitor *> visitors) { 1348 EdgeBuilder EB(PD, PDB); 1349 const SourceManager& SM = PDB.getSourceManager(); 1350 StackDiagVector CallStack; 1351 InterestingExprs IE; 1352 1353 const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin()); 1354 while (NextNode) { 1355 N = NextNode; 1356 NextNode = N->getFirstPred(); 1357 ProgramPoint P = N->getLocation(); 1358 1359 do { 1360 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1361 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1362 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1363 N->getState().getPtr(), Ex, 1364 N->getLocationContext()); 1365 } 1366 1367 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1368 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1369 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1370 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1371 N->getState().getPtr(), Ex, 1372 N->getLocationContext()); 1373 } 1374 1375 PathDiagnosticCallPiece *C = 1376 PathDiagnosticCallPiece::construct(N, *CE, SM); 1377 LCM[&C->path] = CE->getCalleeContext(); 1378 1379 EB.addEdge(C->callReturn, /*AlwaysAdd=*/true, /*IsPostJump=*/true); 1380 EB.flushLocations(); 1381 1382 PD.getActivePath().push_front(C); 1383 PD.pushActivePath(&C->path); 1384 CallStack.push_back(StackDiagPair(C, N)); 1385 break; 1386 } 1387 1388 // Pop the call hierarchy if we are done walking the contents 1389 // of a function call. 1390 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1391 // Add an edge to the start of the function. 1392 const Decl *D = CE->getCalleeContext()->getDecl(); 1393 PathDiagnosticLocation pos = 1394 PathDiagnosticLocation::createBegin(D, SM); 1395 EB.addEdge(pos); 1396 1397 // Flush all locations, and pop the active path. 1398 bool VisitedEntireCall = PD.isWithinCall(); 1399 EB.flushLocations(); 1400 PD.popActivePath(); 1401 PDB.LC = N->getLocationContext(); 1402 1403 // Either we just added a bunch of stuff to the top-level path, or 1404 // we have a previous CallExitEnd. If the former, it means that the 1405 // path terminated within a function call. We must then take the 1406 // current contents of the active path and place it within 1407 // a new PathDiagnosticCallPiece. 1408 PathDiagnosticCallPiece *C; 1409 if (VisitedEntireCall) { 1410 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 1411 } else { 1412 const Decl *Caller = CE->getLocationContext()->getDecl(); 1413 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1414 LCM[&C->path] = CE->getCalleeContext(); 1415 } 1416 1417 C->setCallee(*CE, SM); 1418 EB.addContext(C->getLocation()); 1419 1420 if (!CallStack.empty()) { 1421 assert(CallStack.back().first == C); 1422 CallStack.pop_back(); 1423 } 1424 break; 1425 } 1426 1427 // Note that is important that we update the LocationContext 1428 // after looking at CallExits. CallExit basically adds an 1429 // edge in the *caller*, so we don't want to update the LocationContext 1430 // too soon. 1431 PDB.LC = N->getLocationContext(); 1432 1433 // Block edges. 1434 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1435 // Does this represent entering a call? If so, look at propagating 1436 // interesting symbols across call boundaries. 1437 if (NextNode) { 1438 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1439 const LocationContext *CalleeCtx = PDB.LC; 1440 if (CallerCtx != CalleeCtx) { 1441 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1442 N->getState().getPtr(), 1443 CalleeCtx, CallerCtx); 1444 } 1445 } 1446 1447 // Are we jumping to the head of a loop? Add a special diagnostic. 1448 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1449 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1450 const CompoundStmt *CS = NULL; 1451 1452 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1453 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1454 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1455 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1456 1457 PathDiagnosticEventPiece *p = 1458 new PathDiagnosticEventPiece(L, 1459 "Looping back to the head of the loop"); 1460 p->setPrunable(true); 1461 1462 EB.addEdge(p->getLocation(), true); 1463 PD.getActivePath().push_front(p); 1464 1465 if (CS) { 1466 PathDiagnosticLocation BL = 1467 PathDiagnosticLocation::createEndBrace(CS, SM); 1468 EB.addEdge(BL); 1469 } 1470 } 1471 1472 const CFGBlock *BSrc = BE->getSrc(); 1473 ParentMap &PM = PDB.getParentMap(); 1474 1475 if (const Stmt *Term = BSrc->getTerminator()) { 1476 // Are we jumping past the loop body without ever executing the 1477 // loop (because the condition was false)? 1478 if (isLoopJumpPastBody(Term, &*BE) && 1479 !isInLoopBody(PM, 1480 getStmtBeforeCond(PM, 1481 BSrc->getTerminatorCondition(), 1482 N), 1483 Term)) { 1484 PathDiagnosticLocation L(Term, SM, PDB.LC); 1485 PathDiagnosticEventPiece *PE = 1486 new PathDiagnosticEventPiece(L, "Loop body executed 0 times"); 1487 PE->setPrunable(true); 1488 1489 EB.addEdge(PE->getLocation(), true); 1490 PD.getActivePath().push_front(PE); 1491 } 1492 1493 // In any case, add the terminator as the current statement 1494 // context for control edges. 1495 EB.addContext(Term); 1496 } 1497 1498 break; 1499 } 1500 1501 if (Optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) { 1502 Optional<CFGElement> First = BE->getFirstElement(); 1503 if (Optional<CFGStmt> S = First ? First->getAs<CFGStmt>() : None) { 1504 const Stmt *stmt = S->getStmt(); 1505 if (IsControlFlowExpr(stmt)) { 1506 // Add the proper context for '&&', '||', and '?'. 1507 EB.addContext(stmt); 1508 } 1509 else 1510 EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt()); 1511 } 1512 1513 break; 1514 } 1515 1516 1517 } while (0); 1518 1519 if (!NextNode) 1520 continue; 1521 1522 // Add pieces from custom visitors. 1523 BugReport *R = PDB.getBugReport(); 1524 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1525 E = visitors.end(); 1526 I != E; ++I) { 1527 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 1528 const PathDiagnosticLocation &Loc = p->getLocation(); 1529 EB.addEdge(Loc, true); 1530 PD.getActivePath().push_front(p); 1531 updateStackPiecesWithMessage(p, CallStack); 1532 1533 if (const Stmt *S = Loc.asStmt()) 1534 EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 1535 } 1536 } 1537 } 1538 1539 return PDB.getBugReport()->isValid(); 1540} 1541 1542/// \brief Adds a sanitized control-flow diagnostic edge to a path. 1543static void addEdgeToPath(PathPieces &path, 1544 PathDiagnosticLocation &PrevLoc, 1545 PathDiagnosticLocation NewLoc, 1546 const LocationContext *LC) { 1547 if (!NewLoc.isValid()) 1548 return; 1549 1550 SourceLocation NewLocL = NewLoc.asLocation(); 1551 if (NewLocL.isInvalid() || NewLocL.isMacroID()) 1552 return; 1553 1554 if (!PrevLoc.isValid()) { 1555 PrevLoc = NewLoc; 1556 return; 1557 } 1558 1559 // FIXME: ignore intra-macro edges for now. 1560 if (NewLoc.asLocation().getExpansionLoc() == 1561 PrevLoc.asLocation().getExpansionLoc()) 1562 return; 1563 1564 path.push_front(new PathDiagnosticControlFlowPiece(NewLoc, 1565 PrevLoc)); 1566 PrevLoc = NewLoc; 1567} 1568 1569/// A customized wrapper for CFGBlock::getTerminatorCondition() 1570/// which returns the element for ObjCForCollectionStmts. 1571static const Stmt *getTerminatorCondition(const CFGBlock *B) { 1572 const Stmt *S = B->getTerminatorCondition(); 1573 if (const ObjCForCollectionStmt *FS = 1574 dyn_cast_or_null<ObjCForCollectionStmt>(S)) 1575 return FS->getElement(); 1576 return S; 1577} 1578 1579static bool 1580GenerateAlternateExtensivePathDiagnostic(PathDiagnostic& PD, 1581 PathDiagnosticBuilder &PDB, 1582 const ExplodedNode *N, 1583 LocationContextMap &LCM, 1584 ArrayRef<BugReporterVisitor *> visitors) { 1585 1586 BugReport *report = PDB.getBugReport(); 1587 const SourceManager& SM = PDB.getSourceManager(); 1588 StackDiagVector CallStack; 1589 InterestingExprs IE; 1590 1591 // Record the last location for a given visited stack frame. 1592 llvm::DenseMap<const StackFrameContext *, PathDiagnosticLocation> 1593 PrevLocMap; 1594 PrevLocMap[N->getLocationContext()->getCurrentStackFrame()] = 1595 PD.getLocation(); 1596 1597 const ExplodedNode *NextNode = N->getFirstPred(); 1598 while (NextNode) { 1599 N = NextNode; 1600 NextNode = N->getFirstPred(); 1601 ProgramPoint P = N->getLocation(); 1602 1603 do { 1604 // Have we encountered an entrance to a call? It may be 1605 // the case that we have not encountered a matching 1606 // call exit before this point. This means that the path 1607 // terminated within the call itself. 1608 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1609 // Did we visit an entire call? 1610 bool VisitedEntireCall = PD.isWithinCall(); 1611 PD.popActivePath(); 1612 1613 PathDiagnosticCallPiece *C; 1614 if (VisitedEntireCall) { 1615 PathDiagnosticPiece *P = PD.getActivePath().front().getPtr(); 1616 C = cast<PathDiagnosticCallPiece>(P); 1617 } else { 1618 const Decl *Caller = CE->getLocationContext()->getDecl(); 1619 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1620 1621 // Since we just transferred the path over to the call piece, 1622 // reset the mapping from active to location context. 1623 assert(PD.getActivePath().size() == 1 && 1624 PD.getActivePath().front() == C); 1625 LCM[&PD.getActivePath()] = 0; 1626 1627 // Record the location context mapping for the path within 1628 // the call. 1629 assert(LCM[&C->path] == 0 || 1630 LCM[&C->path] == CE->getCalleeContext()); 1631 LCM[&C->path] = CE->getCalleeContext(); 1632 1633 // If this is the first item in the active path, record 1634 // the new mapping from active path to location context. 1635 const LocationContext *&NewLC = LCM[&PD.getActivePath()]; 1636 if (!NewLC) { 1637 NewLC = N->getLocationContext(); 1638 } 1639 PDB.LC = NewLC; 1640 1641 // Update the previous location in the active path 1642 // since we just created the call piece lazily. 1643 PrevLocMap[PDB.LC->getCurrentStackFrame()] = C->getLocation(); 1644 } 1645 C->setCallee(*CE, SM); 1646 1647 if (!CallStack.empty()) { 1648 assert(CallStack.back().first == C); 1649 CallStack.pop_back(); 1650 } 1651 break; 1652 } 1653 1654 // Query the location context here and the previous location 1655 // as processing CallEnter may change the active path. 1656 PDB.LC = N->getLocationContext(); 1657 1658 // Get the previous location for the current active 1659 // location context. All edges will be based on this 1660 // location, and it will be updated in place. 1661 PathDiagnosticLocation &PrevLoc = 1662 PrevLocMap[PDB.LC->getCurrentStackFrame()]; 1663 1664 // Record the mapping from the active path to the location 1665 // context. 1666 assert(!LCM[&PD.getActivePath()] || 1667 LCM[&PD.getActivePath()] == PDB.LC); 1668 LCM[&PD.getActivePath()] = PDB.LC; 1669 1670 // Have we encountered an exit from a function call? 1671 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1672 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1673 // Propagate the interesting symbols accordingly. 1674 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1675 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1676 N->getState().getPtr(), Ex, 1677 N->getLocationContext()); 1678 } 1679 1680 // We are descending into a call (backwards). Construct 1681 // a new call piece to contain the path pieces for that call. 1682 PathDiagnosticCallPiece *C = 1683 PathDiagnosticCallPiece::construct(N, *CE, SM); 1684 1685 // Record the location context for this call piece. 1686 LCM[&C->path] = CE->getCalleeContext(); 1687 1688 // Add the edge to the return site. 1689 addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn, PDB.LC); 1690 PD.getActivePath().push_front(C); 1691 1692 // Make the contents of the call the active path for now. 1693 PD.pushActivePath(&C->path); 1694 CallStack.push_back(StackDiagPair(C, N)); 1695 break; 1696 } 1697 1698 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1699 // For expressions, make sure we propagate the 1700 // interesting symbols correctly. 1701 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1702 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1703 N->getState().getPtr(), Ex, 1704 N->getLocationContext()); 1705 1706 // Add an edge. If this is an ObjCForCollectionStmt do 1707 // not add an edge here as it appears in the CFG both 1708 // as a terminator and as a terminator condition. 1709 if (!isa<ObjCForCollectionStmt>(PS->getStmt())) { 1710 PathDiagnosticLocation L = 1711 PathDiagnosticLocation(PS->getStmt(), SM, PDB.LC); 1712 addEdgeToPath(PD.getActivePath(), PrevLoc, L, PDB.LC); 1713 } 1714 break; 1715 } 1716 1717 // Block edges. 1718 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1719 // Does this represent entering a call? If so, look at propagating 1720 // interesting symbols across call boundaries. 1721 if (NextNode) { 1722 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1723 const LocationContext *CalleeCtx = PDB.LC; 1724 if (CallerCtx != CalleeCtx) { 1725 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1726 N->getState().getPtr(), 1727 CalleeCtx, CallerCtx); 1728 } 1729 } 1730 1731 // Are we jumping to the head of a loop? Add a special diagnostic. 1732 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1733 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1734 const CompoundStmt *CS = NULL; 1735 1736 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1737 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1738 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1739 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1740 else if (const ObjCForCollectionStmt *OFS = 1741 dyn_cast<ObjCForCollectionStmt>(Loop)) { 1742 CS = dyn_cast<CompoundStmt>(OFS->getBody()); 1743 } 1744 1745 PathDiagnosticEventPiece *p = 1746 new PathDiagnosticEventPiece(L, "Looping back to the head " 1747 "of the loop"); 1748 p->setPrunable(true); 1749 1750 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), PDB.LC); 1751 PD.getActivePath().push_front(p); 1752 1753 if (CS) { 1754 addEdgeToPath(PD.getActivePath(), PrevLoc, 1755 PathDiagnosticLocation::createEndBrace(CS, SM), 1756 PDB.LC); 1757 } 1758 } 1759 1760 const CFGBlock *BSrc = BE->getSrc(); 1761 ParentMap &PM = PDB.getParentMap(); 1762 1763 if (const Stmt *Term = BSrc->getTerminator()) { 1764 // Are we jumping past the loop body without ever executing the 1765 // loop (because the condition was false)? 1766 if (isLoop(Term)) { 1767 const Stmt *TermCond = getTerminatorCondition(BSrc); 1768 bool IsInLoopBody = 1769 isInLoopBody(PM, getStmtBeforeCond(PM, TermCond, N), Term); 1770 1771 const char *str = 0; 1772 1773 if (isJumpToFalseBranch(&*BE)) { 1774 if (!IsInLoopBody) { 1775 str = "Loop body executed 0 times"; 1776 } 1777 } 1778 else { 1779 str = "Entering loop body"; 1780 } 1781 1782 if (str) { 1783 PathDiagnosticLocation L(TermCond, SM, PDB.LC); 1784 PathDiagnosticEventPiece *PE = 1785 new PathDiagnosticEventPiece(L, str); 1786 PE->setPrunable(true); 1787 addEdgeToPath(PD.getActivePath(), PrevLoc, 1788 PE->getLocation(), PDB.LC); 1789 PD.getActivePath().push_front(PE); 1790 } 1791 } 1792 else if (isa<BreakStmt>(Term) || isa<ContinueStmt>(Term) || 1793 isa<GotoStmt>(Term)) { 1794 PathDiagnosticLocation L(Term, SM, PDB.LC); 1795 addEdgeToPath(PD.getActivePath(), PrevLoc, L, PDB.LC); 1796 } 1797 } 1798 break; 1799 } 1800 } while (0); 1801 1802 if (!NextNode) 1803 continue; 1804 1805 // Since the active path may have been updated prior 1806 // to this point, query the active location context now. 1807 PathDiagnosticLocation &PrevLoc = 1808 PrevLocMap[PDB.LC->getCurrentStackFrame()]; 1809 1810 // Add pieces from custom visitors. 1811 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1812 E = visitors.end(); 1813 I != E; ++I) { 1814 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *report)) { 1815 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), PDB.LC); 1816 PD.getActivePath().push_front(p); 1817 updateStackPiecesWithMessage(p, CallStack); 1818 } 1819 } 1820 } 1821 1822 return report->isValid(); 1823} 1824 1825const Stmt *getLocStmt(PathDiagnosticLocation L) { 1826 if (!L.isValid()) 1827 return 0; 1828 return L.asStmt(); 1829} 1830 1831const Stmt *getStmtParent(const Stmt *S, ParentMap &PM) { 1832 if (!S) 1833 return 0; 1834 1835 while (true) { 1836 S = PM.getParentIgnoreParens(S); 1837 1838 if (!S) 1839 break; 1840 1841 if (isa<ExprWithCleanups>(S)) 1842 continue; 1843 1844 break; 1845 } 1846 1847 return S; 1848} 1849 1850static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) { 1851 switch (S->getStmtClass()) { 1852 case Stmt::BinaryOperatorClass: { 1853 const BinaryOperator *BO = cast<BinaryOperator>(S); 1854 if (!BO->isLogicalOp()) 1855 return false; 1856 return BO->getLHS() == Cond || BO->getRHS() == Cond; 1857 } 1858 case Stmt::IfStmtClass: 1859 return cast<IfStmt>(S)->getCond() == Cond; 1860 case Stmt::ForStmtClass: 1861 return cast<ForStmt>(S)->getCond() == Cond; 1862 case Stmt::WhileStmtClass: 1863 return cast<WhileStmt>(S)->getCond() == Cond; 1864 case Stmt::DoStmtClass: 1865 return cast<DoStmt>(S)->getCond() == Cond; 1866 case Stmt::ChooseExprClass: 1867 return cast<ChooseExpr>(S)->getCond() == Cond; 1868 case Stmt::IndirectGotoStmtClass: 1869 return cast<IndirectGotoStmt>(S)->getTarget() == Cond; 1870 case Stmt::SwitchStmtClass: 1871 return cast<SwitchStmt>(S)->getCond() == Cond; 1872 case Stmt::BinaryConditionalOperatorClass: 1873 return cast<BinaryConditionalOperator>(S)->getCond() == Cond; 1874 case Stmt::ConditionalOperatorClass: { 1875 const ConditionalOperator *CO = cast<ConditionalOperator>(S); 1876 return CO->getCond() == Cond || 1877 CO->getLHS() == Cond || 1878 CO->getRHS() == Cond; 1879 } 1880 case Stmt::ObjCForCollectionStmtClass: 1881 return cast<ObjCForCollectionStmt>(S)->getElement() == Cond; 1882 default: 1883 return false; 1884 } 1885} 1886 1887static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) { 1888 const ForStmt *FS = dyn_cast<ForStmt>(FL); 1889 if (!FS) 1890 return false; 1891 return FS->getInc() == S || FS->getInit() == S; 1892} 1893 1894typedef llvm::DenseSet<const PathDiagnosticCallPiece *> 1895 OptimizedCallsSet; 1896 1897void PathPieces::dump() const { 1898 unsigned index = 0; 1899 for (PathPieces::const_iterator I = begin(), E = end(); I != E; ++I ) { 1900 llvm::errs() << "[" << index++ << "]"; 1901 1902 switch ((*I)->getKind()) { 1903 case PathDiagnosticPiece::Call: 1904 llvm::errs() << " CALL\n--------------\n"; 1905 1906 if (const Stmt *SLoc = getLocStmt((*I)->getLocation())) { 1907 SLoc->dump(); 1908 } else { 1909 const PathDiagnosticCallPiece *Call = cast<PathDiagnosticCallPiece>(*I); 1910 if (const NamedDecl *ND = dyn_cast<NamedDecl>(Call->getCallee())) 1911 llvm::errs() << *ND << "\n"; 1912 } 1913 break; 1914 case PathDiagnosticPiece::Event: 1915 llvm::errs() << " EVENT\n--------------\n"; 1916 llvm::errs() << (*I)->getString() << "\n"; 1917 if (const Stmt *SLoc = getLocStmt((*I)->getLocation())) { 1918 llvm::errs() << " ---- at ----\n"; 1919 SLoc->dump(); 1920 } 1921 break; 1922 case PathDiagnosticPiece::Macro: 1923 llvm::errs() << " MACRO\n--------------\n"; 1924 // FIXME: print which macro is being invoked. 1925 break; 1926 case PathDiagnosticPiece::ControlFlow: { 1927 const PathDiagnosticControlFlowPiece *CP = 1928 cast<PathDiagnosticControlFlowPiece>(*I); 1929 llvm::errs() << " CONTROL\n--------------\n"; 1930 1931 if (const Stmt *s1Start = getLocStmt(CP->getStartLocation())) 1932 s1Start->dump(); 1933 else 1934 llvm::errs() << "NULL\n"; 1935 1936 llvm::errs() << " ---- to ----\n"; 1937 1938 if (const Stmt *s1End = getLocStmt(CP->getEndLocation())) 1939 s1End->dump(); 1940 else 1941 llvm::errs() << "NULL\n"; 1942 1943 break; 1944 } 1945 } 1946 1947 llvm::errs() << "\n"; 1948 } 1949} 1950 1951static bool optimizeEdges(PathPieces &path, SourceManager &SM, 1952 OptimizedCallsSet &OCS, 1953 LocationContextMap &LCM) { 1954 bool hasChanges = false; 1955 const LocationContext *LC = LCM[&path]; 1956 assert(LC); 1957 bool isFirst = true; 1958 1959 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) { 1960 bool wasFirst = isFirst; 1961 isFirst = false; 1962 1963 // Optimize subpaths. 1964 if (PathDiagnosticCallPiece *CallI = dyn_cast<PathDiagnosticCallPiece>(*I)){ 1965 // Record the fact that a call has been optimized so we only do the 1966 // effort once. 1967 if (!OCS.count(CallI)) { 1968 while (optimizeEdges(CallI->path, SM, OCS, LCM)) {} 1969 OCS.insert(CallI); 1970 } 1971 ++I; 1972 continue; 1973 } 1974 1975 // Pattern match the current piece and its successor. 1976 PathDiagnosticControlFlowPiece *PieceI = 1977 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 1978 1979 if (!PieceI) { 1980 ++I; 1981 continue; 1982 } 1983 1984 ParentMap &PM = LC->getParentMap(); 1985 const Stmt *s1Start = getLocStmt(PieceI->getStartLocation()); 1986 const Stmt *s1End = getLocStmt(PieceI->getEndLocation()); 1987 const Stmt *level1 = getStmtParent(s1Start, PM); 1988 const Stmt *level2 = getStmtParent(s1End, PM); 1989 1990 if (wasFirst) { 1991 wasFirst = false; 1992 1993 // If the first edge (in isolation) is just a transition from 1994 // an expression to a parent expression then eliminate that edge. 1995 if (level1 && level2 && level2 == PM.getParent(level1)) { 1996 path.erase(I); 1997 // Since we are erasing the current edge at the start of the 1998 // path, just return now so we start analyzing the start of the path 1999 // again. 2000 return true; 2001 } 2002 2003 // If the first edge (in isolation) is a transition from the 2004 // initialization or increment in a for loop then remove it. 2005 if (level1 && isIncrementOrInitInForLoop(s1Start, level1)) { 2006 path.erase(I); 2007 return true; 2008 } 2009 } 2010 2011 PathPieces::iterator NextI = I; ++NextI; 2012 if (NextI == E) 2013 break; 2014 2015 PathDiagnosticControlFlowPiece *PieceNextI = 2016 dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 2017 2018 if (!PieceNextI) { 2019 ++I; 2020 continue; 2021 } 2022 2023 const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation()); 2024 const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation()); 2025 const Stmt *level3 = getStmtParent(s2Start, PM); 2026 const Stmt *level4 = getStmtParent(s2End, PM); 2027 2028 // Rule I. 2029 // 2030 // If we have two consecutive control edges whose end/begin locations 2031 // are at the same level (e.g. statements or top-level expressions within 2032 // a compound statement, or siblings share a single ancestor expression), 2033 // then merge them if they have no interesting intermediate event. 2034 // 2035 // For example: 2036 // 2037 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common 2038 // parent is '1'. Here 'x.y.z' represents the hierarchy of statements. 2039 // 2040 // NOTE: this will be limited later in cases where we add barriers 2041 // to prevent this optimization. 2042 // 2043 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) { 2044 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2045 path.erase(NextI); 2046 hasChanges = true; 2047 continue; 2048 } 2049 2050 // Rule II. 2051 // 2052 // Eliminate edges between subexpressions and parent expressions 2053 // when the subexpression is consumed. 2054 // 2055 // NOTE: this will be limited later in cases where we add barriers 2056 // to prevent this optimization. 2057 // 2058 if (s1End && s1End == s2Start && level2) { 2059 if (isIncrementOrInitInForLoop(s1End, level2) || 2060 (isa<Expr>(s1End) && PM.isConsumedExpr(cast<Expr>(s1End)) && 2061 !isConditionForTerminator(level2, s1End))) 2062 { 2063 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2064 path.erase(NextI); 2065 hasChanges = true; 2066 continue; 2067 } 2068 } 2069 2070 // Optimize edges for ObjC fast-enumeration loops. 2071 // 2072 // (X -> collection) -> (collection -> element) 2073 // 2074 // becomes: 2075 // 2076 // (X -> element) 2077 if (s1End == s2Start) { 2078 const ObjCForCollectionStmt *FS = 2079 dyn_cast_or_null<ObjCForCollectionStmt>(level3); 2080 if (FS && FS->getCollection()->IgnoreParens() == s2Start && 2081 s2End == FS->getElement()) { 2082 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2083 path.erase(NextI); 2084 hasChanges = true; 2085 continue; 2086 } 2087 } 2088 2089 // No changes at this index? Move to the next one. 2090 ++I; 2091 } 2092 2093 // No changes. 2094 return hasChanges; 2095} 2096 2097static void adjustBranchEdges(PathPieces &pieces, LocationContextMap &LCM, 2098 SourceManager &SM) { 2099 // Retrieve the parent map for this path. 2100 const LocationContext *LC = LCM[&pieces]; 2101 ParentMap &PM = LC->getParentMap(); 2102 PathPieces::iterator Prev = pieces.end(); 2103 for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; 2104 Prev = I, ++I) { 2105 // Adjust edges in subpaths. 2106 if (PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I)) { 2107 adjustBranchEdges(Call->path, LCM, SM); 2108 continue; 2109 } 2110 2111 PathDiagnosticControlFlowPiece *PieceI = 2112 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 2113 2114 if (!PieceI) 2115 continue; 2116 2117 // We are looking at two edges. Is the second one incident 2118 // on an expression (or subexpression) of a branch condition. 2119 const Stmt *Dst = getLocStmt(PieceI->getEndLocation()); 2120 const Stmt *Src = getLocStmt(PieceI->getStartLocation()); 2121 2122 if (!Dst || !Src) 2123 continue; 2124 2125 const Stmt *Branch = 0; 2126 const Stmt *S = Dst; 2127 while (const Stmt *Parent = getStmtParent(S, PM)) { 2128 if (const ForStmt *FS = dyn_cast<ForStmt>(Parent)) { 2129 if (FS->getCond()->IgnoreParens() == S) 2130 Branch = FS; 2131 break; 2132 } 2133 if (const WhileStmt *WS = dyn_cast<WhileStmt>(Parent)) { 2134 if (WS->getCond()->IgnoreParens() == S) 2135 Branch = WS; 2136 break; 2137 } 2138 if (const IfStmt *IS = dyn_cast<IfStmt>(Parent)) { 2139 if (IS->getCond()->IgnoreParens() == S) 2140 Branch = IS; 2141 break; 2142 } 2143 if (const ObjCForCollectionStmt *OFS = 2144 dyn_cast<ObjCForCollectionStmt>(Parent)) { 2145 if (OFS->getElement() == S) 2146 Branch = OFS; 2147 break; 2148 } 2149 2150 S = Parent; 2151 } 2152 2153 // If 'Branch' is non-null we have found a match where we have an edge 2154 // incident on the condition of a if/for/while statement. 2155 if (!Branch) 2156 continue; 2157 2158 // If the current source of the edge is the if/for/while, then there is 2159 // nothing left to be done. 2160 if (Src == Branch) 2161 continue; 2162 2163 // Now look at the previous edge. We want to know if this was in the same 2164 // "level" as the for statement. 2165 const Stmt *SrcParent = getStmtParent(Src, PM); 2166 const Stmt *BranchParent = getStmtParent(Branch, PM); 2167 if (SrcParent && SrcParent == BranchParent) { 2168 PathDiagnosticLocation L(Branch, SM, LC); 2169 bool needsEdge = true; 2170 2171 if (Prev != E) { 2172 if (PathDiagnosticControlFlowPiece *P = 2173 dyn_cast<PathDiagnosticControlFlowPiece>(*Prev)) { 2174 const Stmt *PrevSrc = getLocStmt(P->getStartLocation()); 2175 if (PrevSrc) { 2176 const Stmt *PrevSrcParent = getStmtParent(PrevSrc, PM); 2177 if (PrevSrcParent == BranchParent) { 2178 P->setEndLocation(L); 2179 needsEdge = false; 2180 } 2181 } 2182 } 2183 } 2184 2185 if (needsEdge) { 2186 PathDiagnosticControlFlowPiece *P = 2187 new PathDiagnosticControlFlowPiece(PieceI->getStartLocation(), L); 2188 pieces.insert(I, P); 2189 } 2190 2191 PieceI->setStartLocation(L); 2192 } 2193 } 2194} 2195 2196//===----------------------------------------------------------------------===// 2197// Methods for BugType and subclasses. 2198//===----------------------------------------------------------------------===// 2199BugType::~BugType() { } 2200 2201void BugType::FlushReports(BugReporter &BR) {} 2202 2203void BuiltinBug::anchor() {} 2204 2205//===----------------------------------------------------------------------===// 2206// Methods for BugReport and subclasses. 2207//===----------------------------------------------------------------------===// 2208 2209void BugReport::NodeResolver::anchor() {} 2210 2211void BugReport::addVisitor(BugReporterVisitor* visitor) { 2212 if (!visitor) 2213 return; 2214 2215 llvm::FoldingSetNodeID ID; 2216 visitor->Profile(ID); 2217 void *InsertPos; 2218 2219 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) { 2220 delete visitor; 2221 return; 2222 } 2223 2224 CallbacksSet.InsertNode(visitor, InsertPos); 2225 Callbacks.push_back(visitor); 2226 ++ConfigurationChangeToken; 2227} 2228 2229BugReport::~BugReport() { 2230 for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) { 2231 delete *I; 2232 } 2233 while (!interestingSymbols.empty()) { 2234 popInterestingSymbolsAndRegions(); 2235 } 2236} 2237 2238const Decl *BugReport::getDeclWithIssue() const { 2239 if (DeclWithIssue) 2240 return DeclWithIssue; 2241 2242 const ExplodedNode *N = getErrorNode(); 2243 if (!N) 2244 return 0; 2245 2246 const LocationContext *LC = N->getLocationContext(); 2247 return LC->getCurrentStackFrame()->getDecl(); 2248} 2249 2250void BugReport::Profile(llvm::FoldingSetNodeID& hash) const { 2251 hash.AddPointer(&BT); 2252 hash.AddString(Description); 2253 PathDiagnosticLocation UL = getUniqueingLocation(); 2254 if (UL.isValid()) { 2255 UL.Profile(hash); 2256 } else if (Location.isValid()) { 2257 Location.Profile(hash); 2258 } else { 2259 assert(ErrorNode); 2260 hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode)); 2261 } 2262 2263 for (SmallVectorImpl<SourceRange>::const_iterator I = 2264 Ranges.begin(), E = Ranges.end(); I != E; ++I) { 2265 const SourceRange range = *I; 2266 if (!range.isValid()) 2267 continue; 2268 hash.AddInteger(range.getBegin().getRawEncoding()); 2269 hash.AddInteger(range.getEnd().getRawEncoding()); 2270 } 2271} 2272 2273void BugReport::markInteresting(SymbolRef sym) { 2274 if (!sym) 2275 return; 2276 2277 // If the symbol wasn't already in our set, note a configuration change. 2278 if (getInterestingSymbols().insert(sym).second) 2279 ++ConfigurationChangeToken; 2280 2281 if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym)) 2282 getInterestingRegions().insert(meta->getRegion()); 2283} 2284 2285void BugReport::markInteresting(const MemRegion *R) { 2286 if (!R) 2287 return; 2288 2289 // If the base region wasn't already in our set, note a configuration change. 2290 R = R->getBaseRegion(); 2291 if (getInterestingRegions().insert(R).second) 2292 ++ConfigurationChangeToken; 2293 2294 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2295 getInterestingSymbols().insert(SR->getSymbol()); 2296} 2297 2298void BugReport::markInteresting(SVal V) { 2299 markInteresting(V.getAsRegion()); 2300 markInteresting(V.getAsSymbol()); 2301} 2302 2303void BugReport::markInteresting(const LocationContext *LC) { 2304 if (!LC) 2305 return; 2306 InterestingLocationContexts.insert(LC); 2307} 2308 2309bool BugReport::isInteresting(SVal V) { 2310 return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol()); 2311} 2312 2313bool BugReport::isInteresting(SymbolRef sym) { 2314 if (!sym) 2315 return false; 2316 // We don't currently consider metadata symbols to be interesting 2317 // even if we know their region is interesting. Is that correct behavior? 2318 return getInterestingSymbols().count(sym); 2319} 2320 2321bool BugReport::isInteresting(const MemRegion *R) { 2322 if (!R) 2323 return false; 2324 R = R->getBaseRegion(); 2325 bool b = getInterestingRegions().count(R); 2326 if (b) 2327 return true; 2328 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2329 return getInterestingSymbols().count(SR->getSymbol()); 2330 return false; 2331} 2332 2333bool BugReport::isInteresting(const LocationContext *LC) { 2334 if (!LC) 2335 return false; 2336 return InterestingLocationContexts.count(LC); 2337} 2338 2339void BugReport::lazyInitializeInterestingSets() { 2340 if (interestingSymbols.empty()) { 2341 interestingSymbols.push_back(new Symbols()); 2342 interestingRegions.push_back(new Regions()); 2343 } 2344} 2345 2346BugReport::Symbols &BugReport::getInterestingSymbols() { 2347 lazyInitializeInterestingSets(); 2348 return *interestingSymbols.back(); 2349} 2350 2351BugReport::Regions &BugReport::getInterestingRegions() { 2352 lazyInitializeInterestingSets(); 2353 return *interestingRegions.back(); 2354} 2355 2356void BugReport::pushInterestingSymbolsAndRegions() { 2357 interestingSymbols.push_back(new Symbols(getInterestingSymbols())); 2358 interestingRegions.push_back(new Regions(getInterestingRegions())); 2359} 2360 2361void BugReport::popInterestingSymbolsAndRegions() { 2362 delete interestingSymbols.back(); 2363 interestingSymbols.pop_back(); 2364 delete interestingRegions.back(); 2365 interestingRegions.pop_back(); 2366} 2367 2368const Stmt *BugReport::getStmt() const { 2369 if (!ErrorNode) 2370 return 0; 2371 2372 ProgramPoint ProgP = ErrorNode->getLocation(); 2373 const Stmt *S = NULL; 2374 2375 if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) { 2376 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit(); 2377 if (BE->getBlock() == &Exit) 2378 S = GetPreviousStmt(ErrorNode); 2379 } 2380 if (!S) 2381 S = PathDiagnosticLocation::getStmt(ErrorNode); 2382 2383 return S; 2384} 2385 2386std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator> 2387BugReport::getRanges() { 2388 // If no custom ranges, add the range of the statement corresponding to 2389 // the error node. 2390 if (Ranges.empty()) { 2391 if (const Expr *E = dyn_cast_or_null<Expr>(getStmt())) 2392 addRange(E->getSourceRange()); 2393 else 2394 return std::make_pair(ranges_iterator(), ranges_iterator()); 2395 } 2396 2397 // User-specified absence of range info. 2398 if (Ranges.size() == 1 && !Ranges.begin()->isValid()) 2399 return std::make_pair(ranges_iterator(), ranges_iterator()); 2400 2401 return std::make_pair(Ranges.begin(), Ranges.end()); 2402} 2403 2404PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const { 2405 if (ErrorNode) { 2406 assert(!Location.isValid() && 2407 "Either Location or ErrorNode should be specified but not both."); 2408 return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM); 2409 } else { 2410 assert(Location.isValid()); 2411 return Location; 2412 } 2413 2414 return PathDiagnosticLocation(); 2415} 2416 2417//===----------------------------------------------------------------------===// 2418// Methods for BugReporter and subclasses. 2419//===----------------------------------------------------------------------===// 2420 2421BugReportEquivClass::~BugReportEquivClass() { } 2422GRBugReporter::~GRBugReporter() { } 2423BugReporterData::~BugReporterData() {} 2424 2425ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); } 2426 2427ProgramStateManager& 2428GRBugReporter::getStateManager() { return Eng.getStateManager(); } 2429 2430BugReporter::~BugReporter() { 2431 FlushReports(); 2432 2433 // Free the bug reports we are tracking. 2434 typedef std::vector<BugReportEquivClass *> ContTy; 2435 for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end(); 2436 I != E; ++I) { 2437 delete *I; 2438 } 2439} 2440 2441void BugReporter::FlushReports() { 2442 if (BugTypes.isEmpty()) 2443 return; 2444 2445 // First flush the warnings for each BugType. This may end up creating new 2446 // warnings and new BugTypes. 2447 // FIXME: Only NSErrorChecker needs BugType's FlushReports. 2448 // Turn NSErrorChecker into a proper checker and remove this. 2449 SmallVector<const BugType*, 16> bugTypes; 2450 for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I) 2451 bugTypes.push_back(*I); 2452 for (SmallVector<const BugType*, 16>::iterator 2453 I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I) 2454 const_cast<BugType*>(*I)->FlushReports(*this); 2455 2456 // We need to flush reports in deterministic order to ensure the order 2457 // of the reports is consistent between runs. 2458 typedef std::vector<BugReportEquivClass *> ContVecTy; 2459 for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.end(); 2460 EI != EE; ++EI){ 2461 BugReportEquivClass& EQ = **EI; 2462 FlushReport(EQ); 2463 } 2464 2465 // BugReporter owns and deletes only BugTypes created implicitly through 2466 // EmitBasicReport. 2467 // FIXME: There are leaks from checkers that assume that the BugTypes they 2468 // create will be destroyed by the BugReporter. 2469 for (llvm::StringMap<BugType*>::iterator 2470 I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I) 2471 delete I->second; 2472 2473 // Remove all references to the BugType objects. 2474 BugTypes = F.getEmptySet(); 2475} 2476 2477//===----------------------------------------------------------------------===// 2478// PathDiagnostics generation. 2479//===----------------------------------------------------------------------===// 2480 2481namespace { 2482/// A wrapper around a report graph, which contains only a single path, and its 2483/// node maps. 2484class ReportGraph { 2485public: 2486 InterExplodedGraphMap BackMap; 2487 OwningPtr<ExplodedGraph> Graph; 2488 const ExplodedNode *ErrorNode; 2489 size_t Index; 2490}; 2491 2492/// A wrapper around a trimmed graph and its node maps. 2493class TrimmedGraph { 2494 InterExplodedGraphMap InverseMap; 2495 2496 typedef llvm::DenseMap<const ExplodedNode *, unsigned> PriorityMapTy; 2497 PriorityMapTy PriorityMap; 2498 2499 typedef std::pair<const ExplodedNode *, size_t> NodeIndexPair; 2500 SmallVector<NodeIndexPair, 32> ReportNodes; 2501 2502 OwningPtr<ExplodedGraph> G; 2503 2504 /// A helper class for sorting ExplodedNodes by priority. 2505 template <bool Descending> 2506 class PriorityCompare { 2507 const PriorityMapTy &PriorityMap; 2508 2509 public: 2510 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {} 2511 2512 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const { 2513 PriorityMapTy::const_iterator LI = PriorityMap.find(LHS); 2514 PriorityMapTy::const_iterator RI = PriorityMap.find(RHS); 2515 PriorityMapTy::const_iterator E = PriorityMap.end(); 2516 2517 if (LI == E) 2518 return Descending; 2519 if (RI == E) 2520 return !Descending; 2521 2522 return Descending ? LI->second > RI->second 2523 : LI->second < RI->second; 2524 } 2525 2526 bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const { 2527 return (*this)(LHS.first, RHS.first); 2528 } 2529 }; 2530 2531public: 2532 TrimmedGraph(const ExplodedGraph *OriginalGraph, 2533 ArrayRef<const ExplodedNode *> Nodes); 2534 2535 bool popNextReportGraph(ReportGraph &GraphWrapper); 2536}; 2537} 2538 2539TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph, 2540 ArrayRef<const ExplodedNode *> Nodes) { 2541 // The trimmed graph is created in the body of the constructor to ensure 2542 // that the DenseMaps have been initialized already. 2543 InterExplodedGraphMap ForwardMap; 2544 G.reset(OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap)); 2545 2546 // Find the (first) error node in the trimmed graph. We just need to consult 2547 // the node map which maps from nodes in the original graph to nodes 2548 // in the new graph. 2549 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes; 2550 2551 for (unsigned i = 0, count = Nodes.size(); i < count; ++i) { 2552 if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) { 2553 ReportNodes.push_back(std::make_pair(NewNode, i)); 2554 RemainingNodes.insert(NewNode); 2555 } 2556 } 2557 2558 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph"); 2559 2560 // Perform a forward BFS to find all the shortest paths. 2561 std::queue<const ExplodedNode *> WS; 2562 2563 assert(G->num_roots() == 1); 2564 WS.push(*G->roots_begin()); 2565 unsigned Priority = 0; 2566 2567 while (!WS.empty()) { 2568 const ExplodedNode *Node = WS.front(); 2569 WS.pop(); 2570 2571 PriorityMapTy::iterator PriorityEntry; 2572 bool IsNew; 2573 llvm::tie(PriorityEntry, IsNew) = 2574 PriorityMap.insert(std::make_pair(Node, Priority)); 2575 ++Priority; 2576 2577 if (!IsNew) { 2578 assert(PriorityEntry->second <= Priority); 2579 continue; 2580 } 2581 2582 if (RemainingNodes.erase(Node)) 2583 if (RemainingNodes.empty()) 2584 break; 2585 2586 for (ExplodedNode::const_pred_iterator I = Node->succ_begin(), 2587 E = Node->succ_end(); 2588 I != E; ++I) 2589 WS.push(*I); 2590 } 2591 2592 // Sort the error paths from longest to shortest. 2593 std::sort(ReportNodes.begin(), ReportNodes.end(), 2594 PriorityCompare<true>(PriorityMap)); 2595} 2596 2597bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) { 2598 if (ReportNodes.empty()) 2599 return false; 2600 2601 const ExplodedNode *OrigN; 2602 llvm::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val(); 2603 assert(PriorityMap.find(OrigN) != PriorityMap.end() && 2604 "error node not accessible from root"); 2605 2606 // Create a new graph with a single path. This is the graph 2607 // that will be returned to the caller. 2608 ExplodedGraph *GNew = new ExplodedGraph(); 2609 GraphWrapper.Graph.reset(GNew); 2610 GraphWrapper.BackMap.clear(); 2611 2612 // Now walk from the error node up the BFS path, always taking the 2613 // predeccessor with the lowest number. 2614 ExplodedNode *Succ = 0; 2615 while (true) { 2616 // Create the equivalent node in the new graph with the same state 2617 // and location. 2618 ExplodedNode *NewN = GNew->getNode(OrigN->getLocation(), OrigN->getState(), 2619 OrigN->isSink()); 2620 2621 // Store the mapping to the original node. 2622 InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN); 2623 assert(IMitr != InverseMap.end() && "No mapping to original node."); 2624 GraphWrapper.BackMap[NewN] = IMitr->second; 2625 2626 // Link up the new node with the previous node. 2627 if (Succ) 2628 Succ->addPredecessor(NewN, *GNew); 2629 else 2630 GraphWrapper.ErrorNode = NewN; 2631 2632 Succ = NewN; 2633 2634 // Are we at the final node? 2635 if (OrigN->pred_empty()) { 2636 GNew->addRoot(NewN); 2637 break; 2638 } 2639 2640 // Find the next predeccessor node. We choose the node that is marked 2641 // with the lowest BFS number. 2642 OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(), 2643 PriorityCompare<false>(PriorityMap)); 2644 } 2645 2646 return true; 2647} 2648 2649 2650/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object 2651/// and collapses PathDiagosticPieces that are expanded by macros. 2652static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) { 2653 typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>, 2654 SourceLocation> > MacroStackTy; 2655 2656 typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> > 2657 PiecesTy; 2658 2659 MacroStackTy MacroStack; 2660 PiecesTy Pieces; 2661 2662 for (PathPieces::const_iterator I = path.begin(), E = path.end(); 2663 I!=E; ++I) { 2664 2665 PathDiagnosticPiece *piece = I->getPtr(); 2666 2667 // Recursively compact calls. 2668 if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){ 2669 CompactPathDiagnostic(call->path, SM); 2670 } 2671 2672 // Get the location of the PathDiagnosticPiece. 2673 const FullSourceLoc Loc = piece->getLocation().asLocation(); 2674 2675 // Determine the instantiation location, which is the location we group 2676 // related PathDiagnosticPieces. 2677 SourceLocation InstantiationLoc = Loc.isMacroID() ? 2678 SM.getExpansionLoc(Loc) : 2679 SourceLocation(); 2680 2681 if (Loc.isFileID()) { 2682 MacroStack.clear(); 2683 Pieces.push_back(piece); 2684 continue; 2685 } 2686 2687 assert(Loc.isMacroID()); 2688 2689 // Is the PathDiagnosticPiece within the same macro group? 2690 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) { 2691 MacroStack.back().first->subPieces.push_back(piece); 2692 continue; 2693 } 2694 2695 // We aren't in the same group. Are we descending into a new macro 2696 // or are part of an old one? 2697 IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup; 2698 2699 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ? 2700 SM.getExpansionLoc(Loc) : 2701 SourceLocation(); 2702 2703 // Walk the entire macro stack. 2704 while (!MacroStack.empty()) { 2705 if (InstantiationLoc == MacroStack.back().second) { 2706 MacroGroup = MacroStack.back().first; 2707 break; 2708 } 2709 2710 if (ParentInstantiationLoc == MacroStack.back().second) { 2711 MacroGroup = MacroStack.back().first; 2712 break; 2713 } 2714 2715 MacroStack.pop_back(); 2716 } 2717 2718 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) { 2719 // Create a new macro group and add it to the stack. 2720 PathDiagnosticMacroPiece *NewGroup = 2721 new PathDiagnosticMacroPiece( 2722 PathDiagnosticLocation::createSingleLocation(piece->getLocation())); 2723 2724 if (MacroGroup) 2725 MacroGroup->subPieces.push_back(NewGroup); 2726 else { 2727 assert(InstantiationLoc.isFileID()); 2728 Pieces.push_back(NewGroup); 2729 } 2730 2731 MacroGroup = NewGroup; 2732 MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc)); 2733 } 2734 2735 // Finally, add the PathDiagnosticPiece to the group. 2736 MacroGroup->subPieces.push_back(piece); 2737 } 2738 2739 // Now take the pieces and construct a new PathDiagnostic. 2740 path.clear(); 2741 2742 for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I) 2743 path.push_back(*I); 2744} 2745 2746bool GRBugReporter::generatePathDiagnostic(PathDiagnostic& PD, 2747 PathDiagnosticConsumer &PC, 2748 ArrayRef<BugReport *> &bugReports) { 2749 assert(!bugReports.empty()); 2750 2751 bool HasValid = false; 2752 bool HasInvalid = false; 2753 SmallVector<const ExplodedNode *, 32> errorNodes; 2754 for (ArrayRef<BugReport*>::iterator I = bugReports.begin(), 2755 E = bugReports.end(); I != E; ++I) { 2756 if ((*I)->isValid()) { 2757 HasValid = true; 2758 errorNodes.push_back((*I)->getErrorNode()); 2759 } else { 2760 // Keep the errorNodes list in sync with the bugReports list. 2761 HasInvalid = true; 2762 errorNodes.push_back(0); 2763 } 2764 } 2765 2766 // If all the reports have been marked invalid by a previous path generation, 2767 // we're done. 2768 if (!HasValid) 2769 return false; 2770 2771 typedef PathDiagnosticConsumer::PathGenerationScheme PathGenerationScheme; 2772 PathGenerationScheme ActiveScheme = PC.getGenerationScheme(); 2773 2774 if (ActiveScheme == PathDiagnosticConsumer::Extensive) { 2775 AnalyzerOptions &options = getAnalyzerOptions(); 2776 if (options.getBooleanOption("path-diagnostics-alternate", false)) { 2777 ActiveScheme = PathDiagnosticConsumer::AlternateExtensive; 2778 } 2779 } 2780 2781 TrimmedGraph TrimG(&getGraph(), errorNodes); 2782 ReportGraph ErrorGraph; 2783 2784 while (TrimG.popNextReportGraph(ErrorGraph)) { 2785 // Find the BugReport with the original location. 2786 assert(ErrorGraph.Index < bugReports.size()); 2787 BugReport *R = bugReports[ErrorGraph.Index]; 2788 assert(R && "No original report found for sliced graph."); 2789 assert(R->isValid() && "Report selected by trimmed graph marked invalid."); 2790 2791 // Start building the path diagnostic... 2792 PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, &PC); 2793 const ExplodedNode *N = ErrorGraph.ErrorNode; 2794 2795 // Register additional node visitors. 2796 R->addVisitor(new NilReceiverBRVisitor()); 2797 R->addVisitor(new ConditionBRVisitor()); 2798 R->addVisitor(new LikelyFalsePositiveSuppressionBRVisitor()); 2799 2800 BugReport::VisitorList visitors; 2801 unsigned origReportConfigToken, finalReportConfigToken; 2802 LocationContextMap LCM; 2803 2804 // While generating diagnostics, it's possible the visitors will decide 2805 // new symbols and regions are interesting, or add other visitors based on 2806 // the information they find. If they do, we need to regenerate the path 2807 // based on our new report configuration. 2808 do { 2809 // Get a clean copy of all the visitors. 2810 for (BugReport::visitor_iterator I = R->visitor_begin(), 2811 E = R->visitor_end(); I != E; ++I) 2812 visitors.push_back((*I)->clone()); 2813 2814 // Clear out the active path from any previous work. 2815 PD.resetPath(); 2816 origReportConfigToken = R->getConfigurationChangeToken(); 2817 2818 // Generate the very last diagnostic piece - the piece is visible before 2819 // the trace is expanded. 2820 PathDiagnosticPiece *LastPiece = 0; 2821 for (BugReport::visitor_iterator I = visitors.begin(), E = visitors.end(); 2822 I != E; ++I) { 2823 if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) { 2824 assert (!LastPiece && 2825 "There can only be one final piece in a diagnostic."); 2826 LastPiece = Piece; 2827 } 2828 } 2829 2830 if (ActiveScheme != PathDiagnosticConsumer::None) { 2831 if (!LastPiece) 2832 LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R); 2833 assert(LastPiece); 2834 PD.setEndOfPath(LastPiece); 2835 } 2836 2837 // Make sure we get a clean location context map so we don't 2838 // hold onto old mappings. 2839 LCM.clear(); 2840 2841 switch (ActiveScheme) { 2842 case PathDiagnosticConsumer::AlternateExtensive: 2843 GenerateAlternateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 2844 break; 2845 case PathDiagnosticConsumer::Extensive: 2846 GenerateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 2847 break; 2848 case PathDiagnosticConsumer::Minimal: 2849 GenerateMinimalPathDiagnostic(PD, PDB, N, LCM, visitors); 2850 break; 2851 case PathDiagnosticConsumer::None: 2852 GenerateVisitorsOnlyPathDiagnostic(PD, PDB, N, visitors); 2853 break; 2854 } 2855 2856 // Clean up the visitors we used. 2857 llvm::DeleteContainerPointers(visitors); 2858 2859 // Did anything change while generating this path? 2860 finalReportConfigToken = R->getConfigurationChangeToken(); 2861 } while (finalReportConfigToken != origReportConfigToken); 2862 2863 if (!R->isValid()) 2864 continue; 2865 2866 // Finally, prune the diagnostic path of uninteresting stuff. 2867 if (!PD.path.empty()) { 2868 // Remove messages that are basically the same. 2869 removeRedundantMsgs(PD.getMutablePieces()); 2870 2871 if (R->shouldPrunePath() && getAnalyzerOptions().shouldPrunePaths()) { 2872 bool stillHasNotes = removeUnneededCalls(PD.getMutablePieces(), R, LCM); 2873 assert(stillHasNotes); 2874 (void)stillHasNotes; 2875 } 2876 2877 adjustCallLocations(PD.getMutablePieces()); 2878 2879 if (ActiveScheme == PathDiagnosticConsumer::AlternateExtensive) { 2880 SourceManager &SM = getSourceManager(); 2881 2882 // Reduce the number of edges from a very conservative set 2883 // to an aesthetically pleasing subset that conveys the 2884 // necessary information. 2885 OptimizedCallsSet OCS; 2886 while (optimizeEdges(PD.getMutablePieces(), SM, OCS, LCM)) {} 2887 2888 // Adjust edges into loop conditions to make them more uniform 2889 // and aesthetically pleasing. 2890 adjustBranchEdges(PD.getMutablePieces(), LCM, SM); 2891 } 2892 } 2893 2894 // We found a report and didn't suppress it. 2895 return true; 2896 } 2897 2898 // We suppressed all the reports in this equivalence class. 2899 assert(!HasInvalid && "Inconsistent suppression"); 2900 (void)HasInvalid; 2901 return false; 2902} 2903 2904void BugReporter::Register(BugType *BT) { 2905 BugTypes = F.add(BugTypes, BT); 2906} 2907 2908void BugReporter::emitReport(BugReport* R) { 2909 // Compute the bug report's hash to determine its equivalence class. 2910 llvm::FoldingSetNodeID ID; 2911 R->Profile(ID); 2912 2913 // Lookup the equivance class. If there isn't one, create it. 2914 BugType& BT = R->getBugType(); 2915 Register(&BT); 2916 void *InsertPos; 2917 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos); 2918 2919 if (!EQ) { 2920 EQ = new BugReportEquivClass(R); 2921 EQClasses.InsertNode(EQ, InsertPos); 2922 EQClassesVector.push_back(EQ); 2923 } 2924 else 2925 EQ->AddReport(R); 2926} 2927 2928 2929//===----------------------------------------------------------------------===// 2930// Emitting reports in equivalence classes. 2931//===----------------------------------------------------------------------===// 2932 2933namespace { 2934struct FRIEC_WLItem { 2935 const ExplodedNode *N; 2936 ExplodedNode::const_succ_iterator I, E; 2937 2938 FRIEC_WLItem(const ExplodedNode *n) 2939 : N(n), I(N->succ_begin()), E(N->succ_end()) {} 2940}; 2941} 2942 2943static BugReport * 2944FindReportInEquivalenceClass(BugReportEquivClass& EQ, 2945 SmallVectorImpl<BugReport*> &bugReports) { 2946 2947 BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end(); 2948 assert(I != E); 2949 BugType& BT = I->getBugType(); 2950 2951 // If we don't need to suppress any of the nodes because they are 2952 // post-dominated by a sink, simply add all the nodes in the equivalence class 2953 // to 'Nodes'. Any of the reports will serve as a "representative" report. 2954 if (!BT.isSuppressOnSink()) { 2955 BugReport *R = I; 2956 for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) { 2957 const ExplodedNode *N = I->getErrorNode(); 2958 if (N) { 2959 R = I; 2960 bugReports.push_back(R); 2961 } 2962 } 2963 return R; 2964 } 2965 2966 // For bug reports that should be suppressed when all paths are post-dominated 2967 // by a sink node, iterate through the reports in the equivalence class 2968 // until we find one that isn't post-dominated (if one exists). We use a 2969 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write 2970 // this as a recursive function, but we don't want to risk blowing out the 2971 // stack for very long paths. 2972 BugReport *exampleReport = 0; 2973 2974 for (; I != E; ++I) { 2975 const ExplodedNode *errorNode = I->getErrorNode(); 2976 2977 if (!errorNode) 2978 continue; 2979 if (errorNode->isSink()) { 2980 llvm_unreachable( 2981 "BugType::isSuppressSink() should not be 'true' for sink end nodes"); 2982 } 2983 // No successors? By definition this nodes isn't post-dominated by a sink. 2984 if (errorNode->succ_empty()) { 2985 bugReports.push_back(I); 2986 if (!exampleReport) 2987 exampleReport = I; 2988 continue; 2989 } 2990 2991 // At this point we know that 'N' is not a sink and it has at least one 2992 // successor. Use a DFS worklist to find a non-sink end-of-path node. 2993 typedef FRIEC_WLItem WLItem; 2994 typedef SmallVector<WLItem, 10> DFSWorkList; 2995 llvm::DenseMap<const ExplodedNode *, unsigned> Visited; 2996 2997 DFSWorkList WL; 2998 WL.push_back(errorNode); 2999 Visited[errorNode] = 1; 3000 3001 while (!WL.empty()) { 3002 WLItem &WI = WL.back(); 3003 assert(!WI.N->succ_empty()); 3004 3005 for (; WI.I != WI.E; ++WI.I) { 3006 const ExplodedNode *Succ = *WI.I; 3007 // End-of-path node? 3008 if (Succ->succ_empty()) { 3009 // If we found an end-of-path node that is not a sink. 3010 if (!Succ->isSink()) { 3011 bugReports.push_back(I); 3012 if (!exampleReport) 3013 exampleReport = I; 3014 WL.clear(); 3015 break; 3016 } 3017 // Found a sink? Continue on to the next successor. 3018 continue; 3019 } 3020 // Mark the successor as visited. If it hasn't been explored, 3021 // enqueue it to the DFS worklist. 3022 unsigned &mark = Visited[Succ]; 3023 if (!mark) { 3024 mark = 1; 3025 WL.push_back(Succ); 3026 break; 3027 } 3028 } 3029 3030 // The worklist may have been cleared at this point. First 3031 // check if it is empty before checking the last item. 3032 if (!WL.empty() && &WL.back() == &WI) 3033 WL.pop_back(); 3034 } 3035 } 3036 3037 // ExampleReport will be NULL if all the nodes in the equivalence class 3038 // were post-dominated by sinks. 3039 return exampleReport; 3040} 3041 3042void BugReporter::FlushReport(BugReportEquivClass& EQ) { 3043 SmallVector<BugReport*, 10> bugReports; 3044 BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports); 3045 if (exampleReport) { 3046 const PathDiagnosticConsumers &C = getPathDiagnosticConsumers(); 3047 for (PathDiagnosticConsumers::const_iterator I=C.begin(), 3048 E=C.end(); I != E; ++I) { 3049 FlushReport(exampleReport, **I, bugReports); 3050 } 3051 } 3052} 3053 3054void BugReporter::FlushReport(BugReport *exampleReport, 3055 PathDiagnosticConsumer &PD, 3056 ArrayRef<BugReport*> bugReports) { 3057 3058 // FIXME: Make sure we use the 'R' for the path that was actually used. 3059 // Probably doesn't make a difference in practice. 3060 BugType& BT = exampleReport->getBugType(); 3061 3062 OwningPtr<PathDiagnostic> 3063 D(new PathDiagnostic(exampleReport->getDeclWithIssue(), 3064 exampleReport->getBugType().getName(), 3065 exampleReport->getDescription(), 3066 exampleReport->getShortDescription(/*Fallback=*/false), 3067 BT.getCategory(), 3068 exampleReport->getUniqueingLocation(), 3069 exampleReport->getUniqueingDecl())); 3070 3071 MaxBugClassSize = std::max(bugReports.size(), 3072 static_cast<size_t>(MaxBugClassSize)); 3073 3074 // Generate the full path diagnostic, using the generation scheme 3075 // specified by the PathDiagnosticConsumer. Note that we have to generate 3076 // path diagnostics even for consumers which do not support paths, because 3077 // the BugReporterVisitors may mark this bug as a false positive. 3078 if (!bugReports.empty()) 3079 if (!generatePathDiagnostic(*D.get(), PD, bugReports)) 3080 return; 3081 3082 MaxValidBugClassSize = std::max(bugReports.size(), 3083 static_cast<size_t>(MaxValidBugClassSize)); 3084 3085 // Examine the report and see if the last piece is in a header. Reset the 3086 // report location to the last piece in the main source file. 3087 AnalyzerOptions& Opts = getAnalyzerOptions(); 3088 if (Opts.shouldReportIssuesInMainSourceFile() && !Opts.AnalyzeAll) 3089 D->resetDiagnosticLocationToMainFile(); 3090 3091 // If the path is empty, generate a single step path with the location 3092 // of the issue. 3093 if (D->path.empty()) { 3094 PathDiagnosticLocation L = exampleReport->getLocation(getSourceManager()); 3095 PathDiagnosticPiece *piece = 3096 new PathDiagnosticEventPiece(L, exampleReport->getDescription()); 3097 BugReport::ranges_iterator Beg, End; 3098 llvm::tie(Beg, End) = exampleReport->getRanges(); 3099 for ( ; Beg != End; ++Beg) 3100 piece->addRange(*Beg); 3101 D->setEndOfPath(piece); 3102 } 3103 3104 // Get the meta data. 3105 const BugReport::ExtraTextList &Meta = exampleReport->getExtraText(); 3106 for (BugReport::ExtraTextList::const_iterator i = Meta.begin(), 3107 e = Meta.end(); i != e; ++i) { 3108 D->addMeta(*i); 3109 } 3110 3111 PD.HandlePathDiagnostic(D.take()); 3112} 3113 3114void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, 3115 StringRef name, 3116 StringRef category, 3117 StringRef str, PathDiagnosticLocation Loc, 3118 SourceRange* RBeg, unsigned NumRanges) { 3119 3120 // 'BT' is owned by BugReporter. 3121 BugType *BT = getBugTypeForName(name, category); 3122 BugReport *R = new BugReport(*BT, str, Loc); 3123 R->setDeclWithIssue(DeclWithIssue); 3124 for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg); 3125 emitReport(R); 3126} 3127 3128BugType *BugReporter::getBugTypeForName(StringRef name, 3129 StringRef category) { 3130 SmallString<136> fullDesc; 3131 llvm::raw_svector_ostream(fullDesc) << name << ":" << category; 3132 llvm::StringMapEntry<BugType *> & 3133 entry = StrBugTypes.GetOrCreateValue(fullDesc); 3134 BugType *BT = entry.getValue(); 3135 if (!BT) { 3136 BT = new BugType(name, category); 3137 entry.setValue(BT); 3138 } 3139 return BT; 3140} 3141