BugReporter.cpp revision f468fa16e37fc8fa6a915fe36aee8f0434709789
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 1264/// Return true if the terminator is a loop and the destination is the 1265/// false branch. 1266static bool isLoopJumpPastBody(const Stmt *Term, const BlockEdge *BE) { 1267 switch (Term->getStmtClass()) { 1268 case Stmt::ForStmtClass: 1269 case Stmt::WhileStmtClass: 1270 case Stmt::ObjCForCollectionStmtClass: 1271 break; 1272 default: 1273 // Note that we intentionally do not include do..while here. 1274 return false; 1275 } 1276 1277 // Did we take the false branch? 1278 const CFGBlock *Src = BE->getSrc(); 1279 assert(Src->succ_size() == 2); 1280 return (*(Src->succ_begin()+1) == BE->getDst()); 1281} 1282 1283static bool isContainedByStmt(ParentMap &PM, const Stmt *S, const Stmt *SubS) { 1284 while (SubS) { 1285 if (SubS == S) 1286 return true; 1287 SubS = PM.getParent(SubS); 1288 } 1289 return false; 1290} 1291 1292static const Stmt *getStmtBeforeCond(ParentMap &PM, const Stmt *Term, 1293 const ExplodedNode *N) { 1294 while (N) { 1295 Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>(); 1296 if (SP) { 1297 const Stmt *S = SP->getStmt(); 1298 if (!isContainedByStmt(PM, Term, S)) 1299 return S; 1300 } 1301 N = N->getFirstPred(); 1302 } 1303 return 0; 1304} 1305 1306static bool isInLoopBody(ParentMap &PM, const Stmt *S, const Stmt *Term) { 1307 const Stmt *LoopBody = 0; 1308 switch (Term->getStmtClass()) { 1309 case Stmt::ForStmtClass: { 1310 const ForStmt *FS = cast<ForStmt>(Term); 1311 if (isContainedByStmt(PM, FS->getInc(), S)) 1312 return true; 1313 LoopBody = FS->getBody(); 1314 break; 1315 } 1316 case Stmt::ObjCForCollectionStmtClass: { 1317 const ObjCForCollectionStmt *FC = cast<ObjCForCollectionStmt>(Term); 1318 LoopBody = FC->getBody(); 1319 break; 1320 } 1321 case Stmt::WhileStmtClass: 1322 LoopBody = cast<WhileStmt>(Term)->getBody(); 1323 break; 1324 default: 1325 return false; 1326 } 1327 return isContainedByStmt(PM, LoopBody, S); 1328} 1329 1330//===----------------------------------------------------------------------===// 1331// Top-level logic for generating extensive path diagnostics. 1332//===----------------------------------------------------------------------===// 1333 1334static bool GenerateExtensivePathDiagnostic(PathDiagnostic& PD, 1335 PathDiagnosticBuilder &PDB, 1336 const ExplodedNode *N, 1337 LocationContextMap &LCM, 1338 ArrayRef<BugReporterVisitor *> visitors) { 1339 EdgeBuilder EB(PD, PDB); 1340 const SourceManager& SM = PDB.getSourceManager(); 1341 StackDiagVector CallStack; 1342 InterestingExprs IE; 1343 1344 const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin()); 1345 while (NextNode) { 1346 N = NextNode; 1347 NextNode = N->getFirstPred(); 1348 ProgramPoint P = N->getLocation(); 1349 1350 do { 1351 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1352 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1353 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1354 N->getState().getPtr(), Ex, 1355 N->getLocationContext()); 1356 } 1357 1358 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1359 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1360 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1361 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1362 N->getState().getPtr(), Ex, 1363 N->getLocationContext()); 1364 } 1365 1366 PathDiagnosticCallPiece *C = 1367 PathDiagnosticCallPiece::construct(N, *CE, SM); 1368 LCM[&C->path] = CE->getCalleeContext(); 1369 1370 EB.addEdge(C->callReturn, /*AlwaysAdd=*/true, /*IsPostJump=*/true); 1371 EB.flushLocations(); 1372 1373 PD.getActivePath().push_front(C); 1374 PD.pushActivePath(&C->path); 1375 CallStack.push_back(StackDiagPair(C, N)); 1376 break; 1377 } 1378 1379 // Pop the call hierarchy if we are done walking the contents 1380 // of a function call. 1381 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1382 // Add an edge to the start of the function. 1383 const Decl *D = CE->getCalleeContext()->getDecl(); 1384 PathDiagnosticLocation pos = 1385 PathDiagnosticLocation::createBegin(D, SM); 1386 EB.addEdge(pos); 1387 1388 // Flush all locations, and pop the active path. 1389 bool VisitedEntireCall = PD.isWithinCall(); 1390 EB.flushLocations(); 1391 PD.popActivePath(); 1392 PDB.LC = N->getLocationContext(); 1393 1394 // Either we just added a bunch of stuff to the top-level path, or 1395 // we have a previous CallExitEnd. If the former, it means that the 1396 // path terminated within a function call. We must then take the 1397 // current contents of the active path and place it within 1398 // a new PathDiagnosticCallPiece. 1399 PathDiagnosticCallPiece *C; 1400 if (VisitedEntireCall) { 1401 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 1402 } else { 1403 const Decl *Caller = CE->getLocationContext()->getDecl(); 1404 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1405 LCM[&C->path] = CE->getCalleeContext(); 1406 } 1407 1408 C->setCallee(*CE, SM); 1409 EB.addContext(C->getLocation()); 1410 1411 if (!CallStack.empty()) { 1412 assert(CallStack.back().first == C); 1413 CallStack.pop_back(); 1414 } 1415 break; 1416 } 1417 1418 // Note that is important that we update the LocationContext 1419 // after looking at CallExits. CallExit basically adds an 1420 // edge in the *caller*, so we don't want to update the LocationContext 1421 // too soon. 1422 PDB.LC = N->getLocationContext(); 1423 1424 // Block edges. 1425 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1426 // Does this represent entering a call? If so, look at propagating 1427 // interesting symbols across call boundaries. 1428 if (NextNode) { 1429 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1430 const LocationContext *CalleeCtx = PDB.LC; 1431 if (CallerCtx != CalleeCtx) { 1432 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1433 N->getState().getPtr(), 1434 CalleeCtx, CallerCtx); 1435 } 1436 } 1437 1438 // Are we jumping to the head of a loop? Add a special diagnostic. 1439 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1440 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1441 const CompoundStmt *CS = NULL; 1442 1443 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1444 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1445 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1446 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1447 1448 PathDiagnosticEventPiece *p = 1449 new PathDiagnosticEventPiece(L, 1450 "Looping back to the head of the loop"); 1451 p->setPrunable(true); 1452 1453 EB.addEdge(p->getLocation(), true); 1454 PD.getActivePath().push_front(p); 1455 1456 if (CS) { 1457 PathDiagnosticLocation BL = 1458 PathDiagnosticLocation::createEndBrace(CS, SM); 1459 EB.addEdge(BL); 1460 } 1461 } 1462 1463 const CFGBlock *BSrc = BE->getSrc(); 1464 ParentMap &PM = PDB.getParentMap(); 1465 1466 if (const Stmt *Term = BSrc->getTerminator()) { 1467 // Are we jumping past the loop body without ever executing the 1468 // loop (because the condition was false)? 1469 if (isLoopJumpPastBody(Term, &*BE) && 1470 !isInLoopBody(PM, 1471 getStmtBeforeCond(PM, 1472 BSrc->getTerminatorCondition(), 1473 N), 1474 Term)) { 1475 PathDiagnosticLocation L(Term, SM, PDB.LC); 1476 PathDiagnosticEventPiece *PE = 1477 new PathDiagnosticEventPiece(L, "Loop body executed 0 times"); 1478 PE->setPrunable(true); 1479 1480 EB.addEdge(PE->getLocation(), true); 1481 PD.getActivePath().push_front(PE); 1482 } 1483 1484 // In any case, add the terminator as the current statement 1485 // context for control edges. 1486 EB.addContext(Term); 1487 } 1488 1489 break; 1490 } 1491 1492 if (Optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) { 1493 Optional<CFGElement> First = BE->getFirstElement(); 1494 if (Optional<CFGStmt> S = First ? First->getAs<CFGStmt>() : None) { 1495 const Stmt *stmt = S->getStmt(); 1496 if (IsControlFlowExpr(stmt)) { 1497 // Add the proper context for '&&', '||', and '?'. 1498 EB.addContext(stmt); 1499 } 1500 else 1501 EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt()); 1502 } 1503 1504 break; 1505 } 1506 1507 1508 } while (0); 1509 1510 if (!NextNode) 1511 continue; 1512 1513 // Add pieces from custom visitors. 1514 BugReport *R = PDB.getBugReport(); 1515 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1516 E = visitors.end(); 1517 I != E; ++I) { 1518 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 1519 const PathDiagnosticLocation &Loc = p->getLocation(); 1520 EB.addEdge(Loc, true); 1521 PD.getActivePath().push_front(p); 1522 updateStackPiecesWithMessage(p, CallStack); 1523 1524 if (const Stmt *S = Loc.asStmt()) 1525 EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 1526 } 1527 } 1528 } 1529 1530 return PDB.getBugReport()->isValid(); 1531} 1532 1533/// \brief Adds a sanitized control-flow diagnostic edge to a path. 1534static void addEdgeToPath(PathPieces &path, 1535 PathDiagnosticLocation &PrevLoc, 1536 PathDiagnosticLocation NewLoc, 1537 const LocationContext *LC) { 1538 if (!NewLoc.isValid()) 1539 return; 1540 1541 SourceLocation NewLocL = NewLoc.asLocation(); 1542 if (NewLocL.isInvalid() || NewLocL.isMacroID()) 1543 return; 1544 1545 if (!PrevLoc.isValid()) { 1546 PrevLoc = NewLoc; 1547 return; 1548 } 1549 1550 // FIXME: ignore intra-macro edges for now. 1551 if (NewLoc.asLocation().getExpansionLoc() == 1552 PrevLoc.asLocation().getExpansionLoc()) 1553 return; 1554 1555 path.push_front(new PathDiagnosticControlFlowPiece(NewLoc, 1556 PrevLoc)); 1557 PrevLoc = NewLoc; 1558} 1559 1560static bool 1561GenerateAlternateExtensivePathDiagnostic(PathDiagnostic& PD, 1562 PathDiagnosticBuilder &PDB, 1563 const ExplodedNode *N, 1564 LocationContextMap &LCM, 1565 ArrayRef<BugReporterVisitor *> visitors) { 1566 1567 BugReport *report = PDB.getBugReport(); 1568 const SourceManager& SM = PDB.getSourceManager(); 1569 StackDiagVector CallStack; 1570 InterestingExprs IE; 1571 1572 // Record the last location for a given visited stack frame. 1573 llvm::DenseMap<const StackFrameContext *, PathDiagnosticLocation> 1574 PrevLocMap; 1575 1576 const ExplodedNode *NextNode = N->getFirstPred(); 1577 while (NextNode) { 1578 N = NextNode; 1579 NextNode = N->getFirstPred(); 1580 ProgramPoint P = N->getLocation(); 1581 const LocationContext *LC = N->getLocationContext(); 1582 assert(!LCM[&PD.getActivePath()] || LCM[&PD.getActivePath()] == LC); 1583 LCM[&PD.getActivePath()] = LC; 1584 PathDiagnosticLocation &PrevLoc = PrevLocMap[LC->getCurrentStackFrame()]; 1585 1586 do { 1587 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1588 // For expressions, make sure we propagate the 1589 // interesting symbols correctly. 1590 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1591 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1592 N->getState().getPtr(), Ex, 1593 N->getLocationContext()); 1594 1595 PathDiagnosticLocation L = 1596 PathDiagnosticLocation(PS->getStmt(), SM, LC); 1597 addEdgeToPath(PD.getActivePath(), PrevLoc, L, LC); 1598 break; 1599 } 1600 1601 // Have we encountered an exit from a function call? 1602 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1603 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1604 // Propagate the interesting symbols accordingly. 1605 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1606 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1607 N->getState().getPtr(), Ex, 1608 N->getLocationContext()); 1609 } 1610 1611 // We are descending into a call (backwards). Construct 1612 // a new call piece to contain the path pieces for that call. 1613 PathDiagnosticCallPiece *C = 1614 PathDiagnosticCallPiece::construct(N, *CE, SM); 1615 1616 // Record the location context for this call piece. 1617 LCM[&C->path] = CE->getCalleeContext(); 1618 1619 // Add the edge to the return site. 1620 addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn, LC); 1621 1622 // Make the contents of the call the active path for now. 1623 PD.pushActivePath(&C->path); 1624 CallStack.push_back(StackDiagPair(C, N)); 1625 break; 1626 } 1627 1628 // Have we encountered an entrance to a call? It may be 1629 // the case that we have not encountered a matching 1630 // call exit before this point. This means that the path 1631 // terminated within the call itself. 1632 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1633 // Add an edge to the start of the function. 1634 const Decl *D = CE->getCalleeContext()->getDecl(); 1635 addEdgeToPath(PD.getActivePath(), PrevLoc, 1636 PathDiagnosticLocation::createBegin(D, SM), LC); 1637 1638 // Did we visit an entire call? 1639 bool VisitedEntireCall = PD.isWithinCall(); 1640 PD.popActivePath(); 1641 1642 PathDiagnosticCallPiece *C; 1643 if (VisitedEntireCall) { 1644 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 1645 } else { 1646 const Decl *Caller = CE->getLocationContext()->getDecl(); 1647 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1648 LCM[&C->path] = CE->getCalleeContext(); 1649 } 1650 C->setCallee(*CE, SM); 1651 1652 if (!CallStack.empty()) { 1653 assert(CallStack.back().first == C); 1654 CallStack.pop_back(); 1655 } 1656 break; 1657 } 1658 1659 // Block edges. 1660 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1661 // Does this represent entering a call? If so, look at propagating 1662 // interesting symbols across call boundaries. 1663 if (NextNode) { 1664 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1665 const LocationContext *CalleeCtx = PDB.LC; 1666 if (CallerCtx != CalleeCtx) { 1667 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1668 N->getState().getPtr(), 1669 CalleeCtx, CallerCtx); 1670 } 1671 } 1672 1673 // Are we jumping to the head of a loop? Add a special diagnostic. 1674 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1675 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1676 const CompoundStmt *CS = NULL; 1677 1678 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1679 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1680 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1681 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1682 1683 PathDiagnosticEventPiece *p = 1684 new PathDiagnosticEventPiece(L, "Looping back to the head " 1685 "of the loop"); 1686 p->setPrunable(true); 1687 1688 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), LC); 1689 PD.getActivePath().push_front(p); 1690 1691 if (CS) { 1692 addEdgeToPath(PD.getActivePath(), PrevLoc, 1693 PathDiagnosticLocation::createEndBrace(CS, SM), LC); 1694 } 1695 } 1696 1697 const CFGBlock *BSrc = BE->getSrc(); 1698 ParentMap &PM = PDB.getParentMap(); 1699 1700 if (const Stmt *Term = BSrc->getTerminator()) { 1701 // Are we jumping past the loop body without ever executing the 1702 // loop (because the condition was false)? 1703 if (isLoopJumpPastBody(Term, &*BE) && 1704 !isInLoopBody(PM, 1705 getStmtBeforeCond(PM, 1706 BSrc->getTerminatorCondition(), 1707 N), 1708 Term)) 1709 { 1710 PathDiagnosticLocation L(Term, SM, PDB.LC); 1711 PathDiagnosticEventPiece *PE = 1712 new PathDiagnosticEventPiece(L, "Loop body executed 0 times"); 1713 PE->setPrunable(true); 1714 addEdgeToPath(PD.getActivePath(), PrevLoc, 1715 PE->getLocation(), LC); 1716 PD.getActivePath().push_front(PE); 1717 } 1718 } 1719 break; 1720 } 1721 } while (0); 1722 1723 if (!NextNode) 1724 continue; 1725 1726 // Add pieces from custom visitors. 1727 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1728 E = visitors.end(); 1729 I != E; ++I) { 1730 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *report)) { 1731 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), LC); 1732 PD.getActivePath().push_front(p); 1733 updateStackPiecesWithMessage(p, CallStack); 1734 } 1735 } 1736 } 1737 1738 return report->isValid(); 1739} 1740 1741const Stmt *getLocStmt(PathDiagnosticLocation L) { 1742 if (!L.isValid()) 1743 return 0; 1744 return L.asStmt(); 1745} 1746 1747const Stmt *getStmtParent(const Stmt *S, ParentMap &PM) { 1748 if (!S) 1749 return 0; 1750 return PM.getParent(S); 1751} 1752 1753static bool optimizeEdges(PathPieces &path, 1754 LocationContextMap &LCM) { 1755 bool hasChanges = false; 1756 const LocationContext *LC = LCM[&path]; 1757 assert(LC); 1758 bool isFirst = true; 1759 1760 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) { 1761 PathPieces::iterator NextI = I; ++NextI; 1762 if (NextI == E) 1763 break; 1764 1765 // Optimize subpaths. 1766 if (PathDiagnosticCallPiece *CallI = dyn_cast<PathDiagnosticCallPiece>(*I)){ 1767 while (optimizeEdges(CallI->path, LCM)) {} 1768 continue; 1769 } 1770 1771 // Pattern match the current piece and its successor. 1772 PathDiagnosticControlFlowPiece *PieceI = 1773 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 1774 1775 if (!PieceI) 1776 continue; 1777 1778 ParentMap &PM = LC->getParentMap(); 1779 const Stmt *s1Start = getLocStmt(PieceI->getStartLocation()); 1780 const Stmt *s1End = getLocStmt(PieceI->getEndLocation()); 1781 const Stmt *level1 = getStmtParent(s1Start, PM); 1782 const Stmt *level2 = getStmtParent(s1End, PM); 1783 1784 if (isFirst) { 1785 isFirst = false; 1786 // Apply the "first edge" case for Rule III. here. 1787 if (level1 && level2 && level2 == PM.getParent(level1)) { 1788 path.erase(I); 1789 // Since we are erasing the current edge at the start of the 1790 // path, just return now so we start analyzing the start of the path 1791 // again. 1792 return true; 1793 } 1794 } 1795 1796 PathDiagnosticControlFlowPiece *PieceNextI = 1797 dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 1798 1799 if (!PieceNextI) 1800 continue; 1801 1802 const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation()); 1803 const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation()); 1804 const Stmt *level3 = getStmtParent(s2Start, PM); 1805 const Stmt *level4 = getStmtParent(s2End, PM); 1806 1807 // Rule I. 1808 // 1809 // If we have two consecutive control edges whose end/begin locations 1810 // are at the same level (i.e., parents), merge them. 1811 // 1812 // For example: 1813 // 1814 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common 1815 // parent is '1'. Here '1.1' represents the hierarchy of statements. 1816 // 1817 // NOTE: this will be limited later in cases where we add barriers 1818 // to prevent this optimization. 1819 // 1820 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) { 1821 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1822 path.erase(NextI); 1823 hasChanges = true; 1824 continue; 1825 } 1826 1827 // Rule II. 1828 // 1829 // If we have two consecutive control edges where we decend to a 1830 // subexpression and then pop out merge them. 1831 // 1832 // NOTE: this will be limited later in cases where we add barriers 1833 // to prevent this optimization. 1834 // 1835 // For example: 1836 // 1837 // (1.1 -> 1.1.1) -> (1.1.1 -> 1.2) becomes (1.1 -> 1.2). 1838 if (level1 && level2 && 1839 level1 == level4 && 1840 level2 == level3 && PM.getParent(level2) == level1) { 1841 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1842 path.erase(NextI); 1843 hasChanges = true; 1844 continue; 1845 } 1846 1847 // Rule III. 1848 // 1849 // Eliminate unnecessary edges where we descend to a subexpression from 1850 // a statement at the same level as our parent. 1851 // 1852 // NOTE: this will be limited later in cases where we add barriers 1853 // to prevent this optimization. 1854 // 1855 // For example: 1856 // 1857 // (1.1 -> 1.1.1) -> (1.1.1 -> X) becomes (1.1 -> X). 1858 // 1859 if (level1 && level2 && level1 == PM.getParent(level2)) { 1860 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1861 path.erase(NextI); 1862 hasChanges = true; 1863 continue; 1864 } 1865 1866 // Rule IV. 1867 // 1868 // Eliminate unnecessary edges where we ascend from a subexpression to 1869 // a statement at the same level as our parent. 1870 // 1871 // NOTE: this will be limited later in cases where we add barriers 1872 // to prevent this optimization. 1873 // 1874 // For example: 1875 // 1876 // (X -> 1.1.1) -> (1.1.1 -> 1.1) becomes (X -> 1.1). 1877 // [first edge] (1.1.1 -> 1.1) -> eliminate 1878 // 1879 if (level2 && level4 && level2 == level3 && level4 == PM.getParent(level2)){ 1880 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1881 path.erase(NextI); 1882 hasChanges = true; 1883 continue; 1884 } 1885 } 1886 1887 // No changes. 1888 return hasChanges; 1889} 1890 1891//===----------------------------------------------------------------------===// 1892// Methods for BugType and subclasses. 1893//===----------------------------------------------------------------------===// 1894BugType::~BugType() { } 1895 1896void BugType::FlushReports(BugReporter &BR) {} 1897 1898void BuiltinBug::anchor() {} 1899 1900//===----------------------------------------------------------------------===// 1901// Methods for BugReport and subclasses. 1902//===----------------------------------------------------------------------===// 1903 1904void BugReport::NodeResolver::anchor() {} 1905 1906void BugReport::addVisitor(BugReporterVisitor* visitor) { 1907 if (!visitor) 1908 return; 1909 1910 llvm::FoldingSetNodeID ID; 1911 visitor->Profile(ID); 1912 void *InsertPos; 1913 1914 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) { 1915 delete visitor; 1916 return; 1917 } 1918 1919 CallbacksSet.InsertNode(visitor, InsertPos); 1920 Callbacks.push_back(visitor); 1921 ++ConfigurationChangeToken; 1922} 1923 1924BugReport::~BugReport() { 1925 for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) { 1926 delete *I; 1927 } 1928 while (!interestingSymbols.empty()) { 1929 popInterestingSymbolsAndRegions(); 1930 } 1931} 1932 1933const Decl *BugReport::getDeclWithIssue() const { 1934 if (DeclWithIssue) 1935 return DeclWithIssue; 1936 1937 const ExplodedNode *N = getErrorNode(); 1938 if (!N) 1939 return 0; 1940 1941 const LocationContext *LC = N->getLocationContext(); 1942 return LC->getCurrentStackFrame()->getDecl(); 1943} 1944 1945void BugReport::Profile(llvm::FoldingSetNodeID& hash) const { 1946 hash.AddPointer(&BT); 1947 hash.AddString(Description); 1948 PathDiagnosticLocation UL = getUniqueingLocation(); 1949 if (UL.isValid()) { 1950 UL.Profile(hash); 1951 } else if (Location.isValid()) { 1952 Location.Profile(hash); 1953 } else { 1954 assert(ErrorNode); 1955 hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode)); 1956 } 1957 1958 for (SmallVectorImpl<SourceRange>::const_iterator I = 1959 Ranges.begin(), E = Ranges.end(); I != E; ++I) { 1960 const SourceRange range = *I; 1961 if (!range.isValid()) 1962 continue; 1963 hash.AddInteger(range.getBegin().getRawEncoding()); 1964 hash.AddInteger(range.getEnd().getRawEncoding()); 1965 } 1966} 1967 1968void BugReport::markInteresting(SymbolRef sym) { 1969 if (!sym) 1970 return; 1971 1972 // If the symbol wasn't already in our set, note a configuration change. 1973 if (getInterestingSymbols().insert(sym).second) 1974 ++ConfigurationChangeToken; 1975 1976 if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym)) 1977 getInterestingRegions().insert(meta->getRegion()); 1978} 1979 1980void BugReport::markInteresting(const MemRegion *R) { 1981 if (!R) 1982 return; 1983 1984 // If the base region wasn't already in our set, note a configuration change. 1985 R = R->getBaseRegion(); 1986 if (getInterestingRegions().insert(R).second) 1987 ++ConfigurationChangeToken; 1988 1989 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 1990 getInterestingSymbols().insert(SR->getSymbol()); 1991} 1992 1993void BugReport::markInteresting(SVal V) { 1994 markInteresting(V.getAsRegion()); 1995 markInteresting(V.getAsSymbol()); 1996} 1997 1998void BugReport::markInteresting(const LocationContext *LC) { 1999 if (!LC) 2000 return; 2001 InterestingLocationContexts.insert(LC); 2002} 2003 2004bool BugReport::isInteresting(SVal V) { 2005 return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol()); 2006} 2007 2008bool BugReport::isInteresting(SymbolRef sym) { 2009 if (!sym) 2010 return false; 2011 // We don't currently consider metadata symbols to be interesting 2012 // even if we know their region is interesting. Is that correct behavior? 2013 return getInterestingSymbols().count(sym); 2014} 2015 2016bool BugReport::isInteresting(const MemRegion *R) { 2017 if (!R) 2018 return false; 2019 R = R->getBaseRegion(); 2020 bool b = getInterestingRegions().count(R); 2021 if (b) 2022 return true; 2023 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2024 return getInterestingSymbols().count(SR->getSymbol()); 2025 return false; 2026} 2027 2028bool BugReport::isInteresting(const LocationContext *LC) { 2029 if (!LC) 2030 return false; 2031 return InterestingLocationContexts.count(LC); 2032} 2033 2034void BugReport::lazyInitializeInterestingSets() { 2035 if (interestingSymbols.empty()) { 2036 interestingSymbols.push_back(new Symbols()); 2037 interestingRegions.push_back(new Regions()); 2038 } 2039} 2040 2041BugReport::Symbols &BugReport::getInterestingSymbols() { 2042 lazyInitializeInterestingSets(); 2043 return *interestingSymbols.back(); 2044} 2045 2046BugReport::Regions &BugReport::getInterestingRegions() { 2047 lazyInitializeInterestingSets(); 2048 return *interestingRegions.back(); 2049} 2050 2051void BugReport::pushInterestingSymbolsAndRegions() { 2052 interestingSymbols.push_back(new Symbols(getInterestingSymbols())); 2053 interestingRegions.push_back(new Regions(getInterestingRegions())); 2054} 2055 2056void BugReport::popInterestingSymbolsAndRegions() { 2057 delete interestingSymbols.back(); 2058 interestingSymbols.pop_back(); 2059 delete interestingRegions.back(); 2060 interestingRegions.pop_back(); 2061} 2062 2063const Stmt *BugReport::getStmt() const { 2064 if (!ErrorNode) 2065 return 0; 2066 2067 ProgramPoint ProgP = ErrorNode->getLocation(); 2068 const Stmt *S = NULL; 2069 2070 if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) { 2071 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit(); 2072 if (BE->getBlock() == &Exit) 2073 S = GetPreviousStmt(ErrorNode); 2074 } 2075 if (!S) 2076 S = PathDiagnosticLocation::getStmt(ErrorNode); 2077 2078 return S; 2079} 2080 2081std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator> 2082BugReport::getRanges() { 2083 // If no custom ranges, add the range of the statement corresponding to 2084 // the error node. 2085 if (Ranges.empty()) { 2086 if (const Expr *E = dyn_cast_or_null<Expr>(getStmt())) 2087 addRange(E->getSourceRange()); 2088 else 2089 return std::make_pair(ranges_iterator(), ranges_iterator()); 2090 } 2091 2092 // User-specified absence of range info. 2093 if (Ranges.size() == 1 && !Ranges.begin()->isValid()) 2094 return std::make_pair(ranges_iterator(), ranges_iterator()); 2095 2096 return std::make_pair(Ranges.begin(), Ranges.end()); 2097} 2098 2099PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const { 2100 if (ErrorNode) { 2101 assert(!Location.isValid() && 2102 "Either Location or ErrorNode should be specified but not both."); 2103 return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM); 2104 } else { 2105 assert(Location.isValid()); 2106 return Location; 2107 } 2108 2109 return PathDiagnosticLocation(); 2110} 2111 2112//===----------------------------------------------------------------------===// 2113// Methods for BugReporter and subclasses. 2114//===----------------------------------------------------------------------===// 2115 2116BugReportEquivClass::~BugReportEquivClass() { } 2117GRBugReporter::~GRBugReporter() { } 2118BugReporterData::~BugReporterData() {} 2119 2120ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); } 2121 2122ProgramStateManager& 2123GRBugReporter::getStateManager() { return Eng.getStateManager(); } 2124 2125BugReporter::~BugReporter() { 2126 FlushReports(); 2127 2128 // Free the bug reports we are tracking. 2129 typedef std::vector<BugReportEquivClass *> ContTy; 2130 for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end(); 2131 I != E; ++I) { 2132 delete *I; 2133 } 2134} 2135 2136void BugReporter::FlushReports() { 2137 if (BugTypes.isEmpty()) 2138 return; 2139 2140 // First flush the warnings for each BugType. This may end up creating new 2141 // warnings and new BugTypes. 2142 // FIXME: Only NSErrorChecker needs BugType's FlushReports. 2143 // Turn NSErrorChecker into a proper checker and remove this. 2144 SmallVector<const BugType*, 16> bugTypes; 2145 for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I) 2146 bugTypes.push_back(*I); 2147 for (SmallVector<const BugType*, 16>::iterator 2148 I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I) 2149 const_cast<BugType*>(*I)->FlushReports(*this); 2150 2151 // We need to flush reports in deterministic order to ensure the order 2152 // of the reports is consistent between runs. 2153 typedef std::vector<BugReportEquivClass *> ContVecTy; 2154 for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.end(); 2155 EI != EE; ++EI){ 2156 BugReportEquivClass& EQ = **EI; 2157 FlushReport(EQ); 2158 } 2159 2160 // BugReporter owns and deletes only BugTypes created implicitly through 2161 // EmitBasicReport. 2162 // FIXME: There are leaks from checkers that assume that the BugTypes they 2163 // create will be destroyed by the BugReporter. 2164 for (llvm::StringMap<BugType*>::iterator 2165 I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I) 2166 delete I->second; 2167 2168 // Remove all references to the BugType objects. 2169 BugTypes = F.getEmptySet(); 2170} 2171 2172//===----------------------------------------------------------------------===// 2173// PathDiagnostics generation. 2174//===----------------------------------------------------------------------===// 2175 2176namespace { 2177/// A wrapper around a report graph, which contains only a single path, and its 2178/// node maps. 2179class ReportGraph { 2180public: 2181 InterExplodedGraphMap BackMap; 2182 OwningPtr<ExplodedGraph> Graph; 2183 const ExplodedNode *ErrorNode; 2184 size_t Index; 2185}; 2186 2187/// A wrapper around a trimmed graph and its node maps. 2188class TrimmedGraph { 2189 InterExplodedGraphMap InverseMap; 2190 2191 typedef llvm::DenseMap<const ExplodedNode *, unsigned> PriorityMapTy; 2192 PriorityMapTy PriorityMap; 2193 2194 typedef std::pair<const ExplodedNode *, size_t> NodeIndexPair; 2195 SmallVector<NodeIndexPair, 32> ReportNodes; 2196 2197 OwningPtr<ExplodedGraph> G; 2198 2199 /// A helper class for sorting ExplodedNodes by priority. 2200 template <bool Descending> 2201 class PriorityCompare { 2202 const PriorityMapTy &PriorityMap; 2203 2204 public: 2205 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {} 2206 2207 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const { 2208 PriorityMapTy::const_iterator LI = PriorityMap.find(LHS); 2209 PriorityMapTy::const_iterator RI = PriorityMap.find(RHS); 2210 PriorityMapTy::const_iterator E = PriorityMap.end(); 2211 2212 if (LI == E) 2213 return Descending; 2214 if (RI == E) 2215 return !Descending; 2216 2217 return Descending ? LI->second > RI->second 2218 : LI->second < RI->second; 2219 } 2220 2221 bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const { 2222 return (*this)(LHS.first, RHS.first); 2223 } 2224 }; 2225 2226public: 2227 TrimmedGraph(const ExplodedGraph *OriginalGraph, 2228 ArrayRef<const ExplodedNode *> Nodes); 2229 2230 bool popNextReportGraph(ReportGraph &GraphWrapper); 2231}; 2232} 2233 2234TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph, 2235 ArrayRef<const ExplodedNode *> Nodes) { 2236 // The trimmed graph is created in the body of the constructor to ensure 2237 // that the DenseMaps have been initialized already. 2238 InterExplodedGraphMap ForwardMap; 2239 G.reset(OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap)); 2240 2241 // Find the (first) error node in the trimmed graph. We just need to consult 2242 // the node map which maps from nodes in the original graph to nodes 2243 // in the new graph. 2244 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes; 2245 2246 for (unsigned i = 0, count = Nodes.size(); i < count; ++i) { 2247 if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) { 2248 ReportNodes.push_back(std::make_pair(NewNode, i)); 2249 RemainingNodes.insert(NewNode); 2250 } 2251 } 2252 2253 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph"); 2254 2255 // Perform a forward BFS to find all the shortest paths. 2256 std::queue<const ExplodedNode *> WS; 2257 2258 assert(G->num_roots() == 1); 2259 WS.push(*G->roots_begin()); 2260 unsigned Priority = 0; 2261 2262 while (!WS.empty()) { 2263 const ExplodedNode *Node = WS.front(); 2264 WS.pop(); 2265 2266 PriorityMapTy::iterator PriorityEntry; 2267 bool IsNew; 2268 llvm::tie(PriorityEntry, IsNew) = 2269 PriorityMap.insert(std::make_pair(Node, Priority)); 2270 ++Priority; 2271 2272 if (!IsNew) { 2273 assert(PriorityEntry->second <= Priority); 2274 continue; 2275 } 2276 2277 if (RemainingNodes.erase(Node)) 2278 if (RemainingNodes.empty()) 2279 break; 2280 2281 for (ExplodedNode::const_pred_iterator I = Node->succ_begin(), 2282 E = Node->succ_end(); 2283 I != E; ++I) 2284 WS.push(*I); 2285 } 2286 2287 // Sort the error paths from longest to shortest. 2288 std::sort(ReportNodes.begin(), ReportNodes.end(), 2289 PriorityCompare<true>(PriorityMap)); 2290} 2291 2292bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) { 2293 if (ReportNodes.empty()) 2294 return false; 2295 2296 const ExplodedNode *OrigN; 2297 llvm::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val(); 2298 assert(PriorityMap.find(OrigN) != PriorityMap.end() && 2299 "error node not accessible from root"); 2300 2301 // Create a new graph with a single path. This is the graph 2302 // that will be returned to the caller. 2303 ExplodedGraph *GNew = new ExplodedGraph(); 2304 GraphWrapper.Graph.reset(GNew); 2305 GraphWrapper.BackMap.clear(); 2306 2307 // Now walk from the error node up the BFS path, always taking the 2308 // predeccessor with the lowest number. 2309 ExplodedNode *Succ = 0; 2310 while (true) { 2311 // Create the equivalent node in the new graph with the same state 2312 // and location. 2313 ExplodedNode *NewN = GNew->getNode(OrigN->getLocation(), OrigN->getState(), 2314 OrigN->isSink()); 2315 2316 // Store the mapping to the original node. 2317 InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN); 2318 assert(IMitr != InverseMap.end() && "No mapping to original node."); 2319 GraphWrapper.BackMap[NewN] = IMitr->second; 2320 2321 // Link up the new node with the previous node. 2322 if (Succ) 2323 Succ->addPredecessor(NewN, *GNew); 2324 else 2325 GraphWrapper.ErrorNode = NewN; 2326 2327 Succ = NewN; 2328 2329 // Are we at the final node? 2330 if (OrigN->pred_empty()) { 2331 GNew->addRoot(NewN); 2332 break; 2333 } 2334 2335 // Find the next predeccessor node. We choose the node that is marked 2336 // with the lowest BFS number. 2337 OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(), 2338 PriorityCompare<false>(PriorityMap)); 2339 } 2340 2341 return true; 2342} 2343 2344 2345/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object 2346/// and collapses PathDiagosticPieces that are expanded by macros. 2347static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) { 2348 typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>, 2349 SourceLocation> > MacroStackTy; 2350 2351 typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> > 2352 PiecesTy; 2353 2354 MacroStackTy MacroStack; 2355 PiecesTy Pieces; 2356 2357 for (PathPieces::const_iterator I = path.begin(), E = path.end(); 2358 I!=E; ++I) { 2359 2360 PathDiagnosticPiece *piece = I->getPtr(); 2361 2362 // Recursively compact calls. 2363 if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){ 2364 CompactPathDiagnostic(call->path, SM); 2365 } 2366 2367 // Get the location of the PathDiagnosticPiece. 2368 const FullSourceLoc Loc = piece->getLocation().asLocation(); 2369 2370 // Determine the instantiation location, which is the location we group 2371 // related PathDiagnosticPieces. 2372 SourceLocation InstantiationLoc = Loc.isMacroID() ? 2373 SM.getExpansionLoc(Loc) : 2374 SourceLocation(); 2375 2376 if (Loc.isFileID()) { 2377 MacroStack.clear(); 2378 Pieces.push_back(piece); 2379 continue; 2380 } 2381 2382 assert(Loc.isMacroID()); 2383 2384 // Is the PathDiagnosticPiece within the same macro group? 2385 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) { 2386 MacroStack.back().first->subPieces.push_back(piece); 2387 continue; 2388 } 2389 2390 // We aren't in the same group. Are we descending into a new macro 2391 // or are part of an old one? 2392 IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup; 2393 2394 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ? 2395 SM.getExpansionLoc(Loc) : 2396 SourceLocation(); 2397 2398 // Walk the entire macro stack. 2399 while (!MacroStack.empty()) { 2400 if (InstantiationLoc == MacroStack.back().second) { 2401 MacroGroup = MacroStack.back().first; 2402 break; 2403 } 2404 2405 if (ParentInstantiationLoc == MacroStack.back().second) { 2406 MacroGroup = MacroStack.back().first; 2407 break; 2408 } 2409 2410 MacroStack.pop_back(); 2411 } 2412 2413 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) { 2414 // Create a new macro group and add it to the stack. 2415 PathDiagnosticMacroPiece *NewGroup = 2416 new PathDiagnosticMacroPiece( 2417 PathDiagnosticLocation::createSingleLocation(piece->getLocation())); 2418 2419 if (MacroGroup) 2420 MacroGroup->subPieces.push_back(NewGroup); 2421 else { 2422 assert(InstantiationLoc.isFileID()); 2423 Pieces.push_back(NewGroup); 2424 } 2425 2426 MacroGroup = NewGroup; 2427 MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc)); 2428 } 2429 2430 // Finally, add the PathDiagnosticPiece to the group. 2431 MacroGroup->subPieces.push_back(piece); 2432 } 2433 2434 // Now take the pieces and construct a new PathDiagnostic. 2435 path.clear(); 2436 2437 for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I) 2438 path.push_back(*I); 2439} 2440 2441bool GRBugReporter::generatePathDiagnostic(PathDiagnostic& PD, 2442 PathDiagnosticConsumer &PC, 2443 ArrayRef<BugReport *> &bugReports) { 2444 assert(!bugReports.empty()); 2445 2446 bool HasValid = false; 2447 bool HasInvalid = false; 2448 SmallVector<const ExplodedNode *, 32> errorNodes; 2449 for (ArrayRef<BugReport*>::iterator I = bugReports.begin(), 2450 E = bugReports.end(); I != E; ++I) { 2451 if ((*I)->isValid()) { 2452 HasValid = true; 2453 errorNodes.push_back((*I)->getErrorNode()); 2454 } else { 2455 // Keep the errorNodes list in sync with the bugReports list. 2456 HasInvalid = true; 2457 errorNodes.push_back(0); 2458 } 2459 } 2460 2461 // If all the reports have been marked invalid by a previous path generation, 2462 // we're done. 2463 if (!HasValid) 2464 return false; 2465 2466 typedef PathDiagnosticConsumer::PathGenerationScheme PathGenerationScheme; 2467 PathGenerationScheme ActiveScheme = PC.getGenerationScheme(); 2468 2469 if (ActiveScheme == PathDiagnosticConsumer::Extensive) { 2470 AnalyzerOptions &options = getEngine().getAnalysisManager().options; 2471 if (options.getBooleanOption("path-diagnostics-alternate", true)) { 2472 ActiveScheme = PathDiagnosticConsumer::AlternateExtensive; 2473 } 2474 } 2475 2476 TrimmedGraph TrimG(&getGraph(), errorNodes); 2477 ReportGraph ErrorGraph; 2478 2479 while (TrimG.popNextReportGraph(ErrorGraph)) { 2480 // Find the BugReport with the original location. 2481 assert(ErrorGraph.Index < bugReports.size()); 2482 BugReport *R = bugReports[ErrorGraph.Index]; 2483 assert(R && "No original report found for sliced graph."); 2484 assert(R->isValid() && "Report selected by trimmed graph marked invalid."); 2485 2486 // Start building the path diagnostic... 2487 PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, &PC); 2488 const ExplodedNode *N = ErrorGraph.ErrorNode; 2489 2490 // Register additional node visitors. 2491 R->addVisitor(new NilReceiverBRVisitor()); 2492 R->addVisitor(new ConditionBRVisitor()); 2493 R->addVisitor(new LikelyFalsePositiveSuppressionBRVisitor()); 2494 2495 BugReport::VisitorList visitors; 2496 unsigned origReportConfigToken, finalReportConfigToken; 2497 LocationContextMap LCM; 2498 2499 // While generating diagnostics, it's possible the visitors will decide 2500 // new symbols and regions are interesting, or add other visitors based on 2501 // the information they find. If they do, we need to regenerate the path 2502 // based on our new report configuration. 2503 do { 2504 // Get a clean copy of all the visitors. 2505 for (BugReport::visitor_iterator I = R->visitor_begin(), 2506 E = R->visitor_end(); I != E; ++I) 2507 visitors.push_back((*I)->clone()); 2508 2509 // Clear out the active path from any previous work. 2510 PD.resetPath(); 2511 origReportConfigToken = R->getConfigurationChangeToken(); 2512 2513 // Generate the very last diagnostic piece - the piece is visible before 2514 // the trace is expanded. 2515 PathDiagnosticPiece *LastPiece = 0; 2516 for (BugReport::visitor_iterator I = visitors.begin(), E = visitors.end(); 2517 I != E; ++I) { 2518 if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) { 2519 assert (!LastPiece && 2520 "There can only be one final piece in a diagnostic."); 2521 LastPiece = Piece; 2522 } 2523 } 2524 2525 if (ActiveScheme != PathDiagnosticConsumer::None) { 2526 if (!LastPiece) 2527 LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R); 2528 assert(LastPiece); 2529 PD.setEndOfPath(LastPiece); 2530 } 2531 2532 // Make sure we get a clean location context map so we don't 2533 // hold onto old mappings. 2534 LCM.clear(); 2535 2536 switch (ActiveScheme) { 2537 case PathDiagnosticConsumer::AlternateExtensive: 2538 GenerateAlternateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 2539 break; 2540 case PathDiagnosticConsumer::Extensive: 2541 GenerateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 2542 break; 2543 case PathDiagnosticConsumer::Minimal: 2544 GenerateMinimalPathDiagnostic(PD, PDB, N, LCM, visitors); 2545 break; 2546 case PathDiagnosticConsumer::None: 2547 GenerateVisitorsOnlyPathDiagnostic(PD, PDB, N, visitors); 2548 break; 2549 } 2550 2551 // Clean up the visitors we used. 2552 llvm::DeleteContainerPointers(visitors); 2553 2554 // Did anything change while generating this path? 2555 finalReportConfigToken = R->getConfigurationChangeToken(); 2556 } while (finalReportConfigToken != origReportConfigToken); 2557 2558 if (!R->isValid()) 2559 continue; 2560 2561 // Finally, prune the diagnostic path of uninteresting stuff. 2562 if (!PD.path.empty()) { 2563 // Remove messages that are basically the same. 2564 removeRedundantMsgs(PD.getMutablePieces()); 2565 2566 if (R->shouldPrunePath() && 2567 getEngine().getAnalysisManager().options.shouldPrunePaths()) { 2568 bool stillHasNotes = removeUnneededCalls(PD.getMutablePieces(), R, LCM); 2569 assert(stillHasNotes); 2570 (void)stillHasNotes; 2571 } 2572 2573 adjustCallLocations(PD.getMutablePieces()); 2574 2575 if (ActiveScheme == PathDiagnosticConsumer::AlternateExtensive) { 2576 while (optimizeEdges(PD.getMutablePieces(), LCM)) {} 2577 } 2578 } 2579 2580 // We found a report and didn't suppress it. 2581 return true; 2582 } 2583 2584 // We suppressed all the reports in this equivalence class. 2585 assert(!HasInvalid && "Inconsistent suppression"); 2586 (void)HasInvalid; 2587 return false; 2588} 2589 2590void BugReporter::Register(BugType *BT) { 2591 BugTypes = F.add(BugTypes, BT); 2592} 2593 2594void BugReporter::emitReport(BugReport* R) { 2595 // Compute the bug report's hash to determine its equivalence class. 2596 llvm::FoldingSetNodeID ID; 2597 R->Profile(ID); 2598 2599 // Lookup the equivance class. If there isn't one, create it. 2600 BugType& BT = R->getBugType(); 2601 Register(&BT); 2602 void *InsertPos; 2603 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos); 2604 2605 if (!EQ) { 2606 EQ = new BugReportEquivClass(R); 2607 EQClasses.InsertNode(EQ, InsertPos); 2608 EQClassesVector.push_back(EQ); 2609 } 2610 else 2611 EQ->AddReport(R); 2612} 2613 2614 2615//===----------------------------------------------------------------------===// 2616// Emitting reports in equivalence classes. 2617//===----------------------------------------------------------------------===// 2618 2619namespace { 2620struct FRIEC_WLItem { 2621 const ExplodedNode *N; 2622 ExplodedNode::const_succ_iterator I, E; 2623 2624 FRIEC_WLItem(const ExplodedNode *n) 2625 : N(n), I(N->succ_begin()), E(N->succ_end()) {} 2626}; 2627} 2628 2629static BugReport * 2630FindReportInEquivalenceClass(BugReportEquivClass& EQ, 2631 SmallVectorImpl<BugReport*> &bugReports) { 2632 2633 BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end(); 2634 assert(I != E); 2635 BugType& BT = I->getBugType(); 2636 2637 // If we don't need to suppress any of the nodes because they are 2638 // post-dominated by a sink, simply add all the nodes in the equivalence class 2639 // to 'Nodes'. Any of the reports will serve as a "representative" report. 2640 if (!BT.isSuppressOnSink()) { 2641 BugReport *R = I; 2642 for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) { 2643 const ExplodedNode *N = I->getErrorNode(); 2644 if (N) { 2645 R = I; 2646 bugReports.push_back(R); 2647 } 2648 } 2649 return R; 2650 } 2651 2652 // For bug reports that should be suppressed when all paths are post-dominated 2653 // by a sink node, iterate through the reports in the equivalence class 2654 // until we find one that isn't post-dominated (if one exists). We use a 2655 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write 2656 // this as a recursive function, but we don't want to risk blowing out the 2657 // stack for very long paths. 2658 BugReport *exampleReport = 0; 2659 2660 for (; I != E; ++I) { 2661 const ExplodedNode *errorNode = I->getErrorNode(); 2662 2663 if (!errorNode) 2664 continue; 2665 if (errorNode->isSink()) { 2666 llvm_unreachable( 2667 "BugType::isSuppressSink() should not be 'true' for sink end nodes"); 2668 } 2669 // No successors? By definition this nodes isn't post-dominated by a sink. 2670 if (errorNode->succ_empty()) { 2671 bugReports.push_back(I); 2672 if (!exampleReport) 2673 exampleReport = I; 2674 continue; 2675 } 2676 2677 // At this point we know that 'N' is not a sink and it has at least one 2678 // successor. Use a DFS worklist to find a non-sink end-of-path node. 2679 typedef FRIEC_WLItem WLItem; 2680 typedef SmallVector<WLItem, 10> DFSWorkList; 2681 llvm::DenseMap<const ExplodedNode *, unsigned> Visited; 2682 2683 DFSWorkList WL; 2684 WL.push_back(errorNode); 2685 Visited[errorNode] = 1; 2686 2687 while (!WL.empty()) { 2688 WLItem &WI = WL.back(); 2689 assert(!WI.N->succ_empty()); 2690 2691 for (; WI.I != WI.E; ++WI.I) { 2692 const ExplodedNode *Succ = *WI.I; 2693 // End-of-path node? 2694 if (Succ->succ_empty()) { 2695 // If we found an end-of-path node that is not a sink. 2696 if (!Succ->isSink()) { 2697 bugReports.push_back(I); 2698 if (!exampleReport) 2699 exampleReport = I; 2700 WL.clear(); 2701 break; 2702 } 2703 // Found a sink? Continue on to the next successor. 2704 continue; 2705 } 2706 // Mark the successor as visited. If it hasn't been explored, 2707 // enqueue it to the DFS worklist. 2708 unsigned &mark = Visited[Succ]; 2709 if (!mark) { 2710 mark = 1; 2711 WL.push_back(Succ); 2712 break; 2713 } 2714 } 2715 2716 // The worklist may have been cleared at this point. First 2717 // check if it is empty before checking the last item. 2718 if (!WL.empty() && &WL.back() == &WI) 2719 WL.pop_back(); 2720 } 2721 } 2722 2723 // ExampleReport will be NULL if all the nodes in the equivalence class 2724 // were post-dominated by sinks. 2725 return exampleReport; 2726} 2727 2728void BugReporter::FlushReport(BugReportEquivClass& EQ) { 2729 SmallVector<BugReport*, 10> bugReports; 2730 BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports); 2731 if (exampleReport) { 2732 const PathDiagnosticConsumers &C = getPathDiagnosticConsumers(); 2733 for (PathDiagnosticConsumers::const_iterator I=C.begin(), 2734 E=C.end(); I != E; ++I) { 2735 FlushReport(exampleReport, **I, bugReports); 2736 } 2737 } 2738} 2739 2740void BugReporter::FlushReport(BugReport *exampleReport, 2741 PathDiagnosticConsumer &PD, 2742 ArrayRef<BugReport*> bugReports) { 2743 2744 // FIXME: Make sure we use the 'R' for the path that was actually used. 2745 // Probably doesn't make a difference in practice. 2746 BugType& BT = exampleReport->getBugType(); 2747 2748 OwningPtr<PathDiagnostic> 2749 D(new PathDiagnostic(exampleReport->getDeclWithIssue(), 2750 exampleReport->getBugType().getName(), 2751 exampleReport->getDescription(), 2752 exampleReport->getShortDescription(/*Fallback=*/false), 2753 BT.getCategory(), 2754 exampleReport->getUniqueingLocation(), 2755 exampleReport->getUniqueingDecl())); 2756 2757 MaxBugClassSize = std::max(bugReports.size(), 2758 static_cast<size_t>(MaxBugClassSize)); 2759 2760 // Generate the full path diagnostic, using the generation scheme 2761 // specified by the PathDiagnosticConsumer. Note that we have to generate 2762 // path diagnostics even for consumers which do not support paths, because 2763 // the BugReporterVisitors may mark this bug as a false positive. 2764 if (!bugReports.empty()) 2765 if (!generatePathDiagnostic(*D.get(), PD, bugReports)) 2766 return; 2767 2768 MaxValidBugClassSize = std::max(bugReports.size(), 2769 static_cast<size_t>(MaxValidBugClassSize)); 2770 2771 // If the path is empty, generate a single step path with the location 2772 // of the issue. 2773 if (D->path.empty()) { 2774 PathDiagnosticLocation L = exampleReport->getLocation(getSourceManager()); 2775 PathDiagnosticPiece *piece = 2776 new PathDiagnosticEventPiece(L, exampleReport->getDescription()); 2777 BugReport::ranges_iterator Beg, End; 2778 llvm::tie(Beg, End) = exampleReport->getRanges(); 2779 for ( ; Beg != End; ++Beg) 2780 piece->addRange(*Beg); 2781 D->setEndOfPath(piece); 2782 } 2783 2784 // Get the meta data. 2785 const BugReport::ExtraTextList &Meta = exampleReport->getExtraText(); 2786 for (BugReport::ExtraTextList::const_iterator i = Meta.begin(), 2787 e = Meta.end(); i != e; ++i) { 2788 D->addMeta(*i); 2789 } 2790 2791 PD.HandlePathDiagnostic(D.take()); 2792} 2793 2794void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, 2795 StringRef name, 2796 StringRef category, 2797 StringRef str, PathDiagnosticLocation Loc, 2798 SourceRange* RBeg, unsigned NumRanges) { 2799 2800 // 'BT' is owned by BugReporter. 2801 BugType *BT = getBugTypeForName(name, category); 2802 BugReport *R = new BugReport(*BT, str, Loc); 2803 R->setDeclWithIssue(DeclWithIssue); 2804 for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg); 2805 emitReport(R); 2806} 2807 2808BugType *BugReporter::getBugTypeForName(StringRef name, 2809 StringRef category) { 2810 SmallString<136> fullDesc; 2811 llvm::raw_svector_ostream(fullDesc) << name << ":" << category; 2812 llvm::StringMapEntry<BugType *> & 2813 entry = StrBugTypes.GetOrCreateValue(fullDesc); 2814 BugType *BT = entry.getValue(); 2815 if (!BT) { 2816 BT = new BugType(name, category); 2817 entry.setValue(BT); 2818 } 2819 return BT; 2820} 2821