BugReporter.cpp revision d0f5faf319550b0504b2f8f822d06a6b0279285b
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 1569enum EventCategorization { EC_None, EC_EnterLoop, EC_LoopingBack }; 1570 1571typedef llvm::DenseMap<const PathDiagnosticEventPiece *, 1572 enum EventCategorization> 1573 EventCategoryMap; 1574 1575 1576static void pruneLoopEvents(PathPieces &path, EventCategoryMap &ECM) { 1577 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) { 1578 if (PathDiagnosticCallPiece *call = dyn_cast<PathDiagnosticCallPiece>(*I)) { 1579 pruneLoopEvents(call->path, ECM); 1580 continue; 1581 } 1582 1583 PathDiagnosticEventPiece *I_event = dyn_cast<PathDiagnosticEventPiece>(*I); 1584 if (!I_event || ECM[I_event] != EC_LoopingBack) 1585 continue; 1586 1587 PathPieces::iterator Next = I; ++Next; 1588 PathDiagnosticEventPiece *Next_event = 0; 1589 for ( ; Next != E ; ++Next) { 1590 Next_event = dyn_cast<PathDiagnosticEventPiece>(*Next); 1591 if (Next_event) 1592 break; 1593 } 1594 1595 if (Next_event) { 1596 EventCategorization E = ECM[Next_event]; 1597 if (E == EC_EnterLoop) { 1598 PathDiagnosticLocation L = I_event->getLocation(); 1599 PathDiagnosticLocation L_next = Next_event->getLocation(); 1600 if (L == L_next) { 1601 path.erase(Next); 1602 } 1603 } 1604 } 1605 } 1606} 1607 1608static bool 1609GenerateAlternateExtensivePathDiagnostic(PathDiagnostic& PD, 1610 PathDiagnosticBuilder &PDB, 1611 const ExplodedNode *N, 1612 LocationContextMap &LCM, 1613 ArrayRef<BugReporterVisitor *> visitors) { 1614 1615 BugReport *report = PDB.getBugReport(); 1616 const SourceManager& SM = PDB.getSourceManager(); 1617 StackDiagVector CallStack; 1618 InterestingExprs IE; 1619 1620 // Record the last location for a given visited stack frame. 1621 llvm::DenseMap<const StackFrameContext *, PathDiagnosticLocation> 1622 PrevLocMap; 1623 1624 EventCategoryMap EventCategory; 1625 1626 const ExplodedNode *NextNode = N->getFirstPred(); 1627 while (NextNode) { 1628 N = NextNode; 1629 NextNode = N->getFirstPred(); 1630 ProgramPoint P = N->getLocation(); 1631 const LocationContext *LC = N->getLocationContext(); 1632 assert(!LCM[&PD.getActivePath()] || LCM[&PD.getActivePath()] == LC); 1633 LCM[&PD.getActivePath()] = LC; 1634 PathDiagnosticLocation &PrevLoc = PrevLocMap[LC->getCurrentStackFrame()]; 1635 1636 do { 1637 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1638 // For expressions, make sure we propagate the 1639 // interesting symbols correctly. 1640 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1641 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1642 N->getState().getPtr(), Ex, 1643 N->getLocationContext()); 1644 1645 PathDiagnosticLocation L = 1646 PathDiagnosticLocation(PS->getStmt(), SM, LC); 1647 addEdgeToPath(PD.getActivePath(), PrevLoc, L, LC); 1648 break; 1649 } 1650 1651 // Have we encountered an exit from a function call? 1652 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1653 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1654 // Propagate the interesting symbols accordingly. 1655 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1656 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1657 N->getState().getPtr(), Ex, 1658 N->getLocationContext()); 1659 } 1660 1661 // We are descending into a call (backwards). Construct 1662 // a new call piece to contain the path pieces for that call. 1663 PathDiagnosticCallPiece *C = 1664 PathDiagnosticCallPiece::construct(N, *CE, SM); 1665 1666 // Record the location context for this call piece. 1667 LCM[&C->path] = CE->getCalleeContext(); 1668 1669 // Add the edge to the return site. 1670 addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn, LC); 1671 1672 // Make the contents of the call the active path for now. 1673 PD.pushActivePath(&C->path); 1674 CallStack.push_back(StackDiagPair(C, N)); 1675 break; 1676 } 1677 1678 // Have we encountered an entrance to a call? It may be 1679 // the case that we have not encountered a matching 1680 // call exit before this point. This means that the path 1681 // terminated within the call itself. 1682 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1683 // Add an edge to the start of the function. 1684 const Decl *D = CE->getCalleeContext()->getDecl(); 1685 addEdgeToPath(PD.getActivePath(), PrevLoc, 1686 PathDiagnosticLocation::createBegin(D, SM), LC); 1687 1688 // Did we visit an entire call? 1689 bool VisitedEntireCall = PD.isWithinCall(); 1690 PD.popActivePath(); 1691 1692 PathDiagnosticCallPiece *C; 1693 if (VisitedEntireCall) { 1694 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 1695 } else { 1696 const Decl *Caller = CE->getLocationContext()->getDecl(); 1697 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1698 LCM[&C->path] = CE->getCalleeContext(); 1699 } 1700 C->setCallee(*CE, SM); 1701 1702 if (!CallStack.empty()) { 1703 assert(CallStack.back().first == C); 1704 CallStack.pop_back(); 1705 } 1706 break; 1707 } 1708 1709 // Block edges. 1710 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1711 // Does this represent entering a call? If so, look at propagating 1712 // interesting symbols across call boundaries. 1713 if (NextNode) { 1714 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1715 const LocationContext *CalleeCtx = PDB.LC; 1716 if (CallerCtx != CalleeCtx) { 1717 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1718 N->getState().getPtr(), 1719 CalleeCtx, CallerCtx); 1720 } 1721 } 1722 1723 // Are we jumping to the head of a loop? Add a special diagnostic. 1724 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1725 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1726 const CompoundStmt *CS = NULL; 1727 1728 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1729 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1730 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1731 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1732 1733 PathDiagnosticEventPiece *p = 1734 new PathDiagnosticEventPiece(L, "Looping back to the head " 1735 "of the loop"); 1736 p->setPrunable(true); 1737 1738 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), LC); 1739 PD.getActivePath().push_front(p); 1740 EventCategory[p] = EC_LoopingBack; 1741 1742 if (CS) { 1743 addEdgeToPath(PD.getActivePath(), PrevLoc, 1744 PathDiagnosticLocation::createEndBrace(CS, SM), LC); 1745 } 1746 } 1747 1748 const CFGBlock *BSrc = BE->getSrc(); 1749 ParentMap &PM = PDB.getParentMap(); 1750 1751 if (const Stmt *Term = BSrc->getTerminator()) { 1752 // Are we jumping past the loop body without ever executing the 1753 // loop (because the condition was false)? 1754 if (isLoop(Term)) { 1755 const Stmt *TermCond = BSrc->getTerminatorCondition(); 1756 bool IsInLoopBody = 1757 isInLoopBody(PM, getStmtBeforeCond(PM, TermCond, N), Term); 1758 1759 const char *str = 0; 1760 enum EventCategorization EC = EC_None; 1761 1762 if (isJumpToFalseBranch(&*BE)) { 1763 if (!IsInLoopBody) { 1764 str = "Loop body executed 0 times"; 1765 } 1766 } 1767 else { 1768 str = "Entering loop body"; 1769 EC = EC_EnterLoop; 1770 } 1771 1772 if (str) { 1773 PathDiagnosticLocation L(TermCond, SM, PDB.LC); 1774 PathDiagnosticEventPiece *PE = 1775 new PathDiagnosticEventPiece(L, str); 1776 EventCategory[PE] = EC; 1777 PE->setPrunable(true); 1778 addEdgeToPath(PD.getActivePath(), PrevLoc, 1779 PE->getLocation(), LC); 1780 PD.getActivePath().push_front(PE); 1781 } 1782 } 1783 } 1784 break; 1785 } 1786 } while (0); 1787 1788 if (!NextNode) 1789 continue; 1790 1791 // Add pieces from custom visitors. 1792 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1793 E = visitors.end(); 1794 I != E; ++I) { 1795 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *report)) { 1796 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), LC); 1797 PD.getActivePath().push_front(p); 1798 updateStackPiecesWithMessage(p, CallStack); 1799 } 1800 } 1801 } 1802 1803 if (report->isValid()) { 1804 // Prune redundant loop diagnostics. 1805 pruneLoopEvents(PD.getMutablePieces(), EventCategory); 1806 } 1807 1808 return report->isValid(); 1809} 1810 1811const Stmt *getLocStmt(PathDiagnosticLocation L) { 1812 if (!L.isValid()) 1813 return 0; 1814 return L.asStmt(); 1815} 1816 1817const Stmt *getStmtParent(const Stmt *S, ParentMap &PM) { 1818 if (!S) 1819 return 0; 1820 return PM.getParentIgnoreParens(S); 1821} 1822 1823#if 0 1824static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) { 1825 // Note that we intentionally to do not handle || and && here. 1826 switch (S->getStmtClass()) { 1827 case Stmt::ForStmtClass: 1828 return cast<ForStmt>(S)->getCond() == Cond; 1829 case Stmt::WhileStmtClass: 1830 return cast<WhileStmt>(S)->getCond() == Cond; 1831 case Stmt::DoStmtClass: 1832 return cast<DoStmt>(S)->getCond() == Cond; 1833 case Stmt::ChooseExprClass: 1834 return cast<ChooseExpr>(S)->getCond() == Cond; 1835 case Stmt::IndirectGotoStmtClass: 1836 return cast<IndirectGotoStmt>(S)->getTarget() == Cond; 1837 case Stmt::SwitchStmtClass: 1838 return cast<SwitchStmt>(S)->getCond() == Cond; 1839 case Stmt::BinaryConditionalOperatorClass: 1840 return cast<BinaryConditionalOperator>(S)->getCond() == Cond; 1841 case Stmt::ConditionalOperatorClass: 1842 return cast<ConditionalOperator>(S)->getCond() == Cond; 1843 case Stmt::ObjCForCollectionStmtClass: 1844 return cast<ObjCForCollectionStmt>(S)->getElement() == Cond; 1845 default: 1846 return false; 1847 } 1848} 1849#endif 1850 1851typedef llvm::DenseSet<const PathDiagnosticControlFlowPiece *> 1852 ControlFlowBarrierSet; 1853 1854typedef llvm::DenseSet<const PathDiagnosticCallPiece *> 1855 OptimizedCallsSet; 1856 1857static bool isBarrier(ControlFlowBarrierSet &CFBS, 1858 const PathDiagnosticControlFlowPiece *P) { 1859 return CFBS.count(P); 1860} 1861 1862static bool optimizeEdges(PathPieces &path, SourceManager &SM, 1863 ControlFlowBarrierSet &CFBS, 1864 OptimizedCallsSet &OCS, 1865 LocationContextMap &LCM) { 1866 bool hasChanges = false; 1867 const LocationContext *LC = LCM[&path]; 1868 assert(LC); 1869 bool isFirst = true; 1870 1871 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) { 1872 bool wasFirst = isFirst; 1873 isFirst = false; 1874 1875 // Optimize subpaths. 1876 if (PathDiagnosticCallPiece *CallI = dyn_cast<PathDiagnosticCallPiece>(*I)){ 1877 // Record the fact that a call has been optimized so we only do the 1878 // effort once. 1879 if (!OCS.count(CallI)) { 1880 while (optimizeEdges(CallI->path, SM, CFBS, OCS, LCM)) {} 1881 OCS.insert(CallI); 1882 } 1883 ++I; 1884 continue; 1885 } 1886 1887 // Pattern match the current piece and its successor. 1888 PathDiagnosticControlFlowPiece *PieceI = 1889 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 1890 1891 if (!PieceI) { 1892 ++I; 1893 continue; 1894 } 1895 1896 ParentMap &PM = LC->getParentMap(); 1897 const Stmt *s1Start = getLocStmt(PieceI->getStartLocation()); 1898 const Stmt *s1End = getLocStmt(PieceI->getEndLocation()); 1899 const Stmt *level1 = getStmtParent(s1Start, PM); 1900 const Stmt *level2 = getStmtParent(s1End, PM); 1901 1902 if (wasFirst) { 1903#if 0 1904 // Apply the "first edge" case for Rule V. here. 1905 if (s1Start && level1 && isConditionForTerminator(level1, s1Start)) { 1906 PathDiagnosticLocation NewLoc(level2, SM, LC); 1907 PieceI->setStartLocation(NewLoc); 1908 CFBS.insert(PieceI); 1909 return true; 1910 } 1911#endif 1912 // Apply the "first edge" case for Rule III. here. 1913 if (!isBarrier(CFBS, PieceI) && 1914 level1 && level2 && level2 == PM.getParent(level1)) { 1915 path.erase(I); 1916 // Since we are erasing the current edge at the start of the 1917 // path, just return now so we start analyzing the start of the path 1918 // again. 1919 return true; 1920 } 1921 } 1922 1923 PathPieces::iterator NextI = I; ++NextI; 1924 if (NextI == E) 1925 break; 1926 1927 PathDiagnosticControlFlowPiece *PieceNextI = 1928 dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 1929 1930 if (!PieceNextI) { 1931 ++I; 1932 continue; 1933 } 1934 1935 const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation()); 1936 const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation()); 1937 const Stmt *level3 = getStmtParent(s2Start, PM); 1938 const Stmt *level4 = getStmtParent(s2End, PM); 1939 1940 // Rule I. 1941 // 1942 // If we have two consecutive control edges whose end/begin locations 1943 // are at the same level (e.g. statements or top-level expressions within 1944 // a compound statement, or siblings share a single ancestor expression), 1945 // then merge them if they have no interesting intermediate event. 1946 // 1947 // For example: 1948 // 1949 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common 1950 // parent is '1'. Here 'x.y.z' represents the hierarchy of statements. 1951 // 1952 // NOTE: this will be limited later in cases where we add barriers 1953 // to prevent this optimization. 1954 // 1955 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) { 1956 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1957 path.erase(NextI); 1958 hasChanges = true; 1959 continue; 1960 } 1961 1962 // Rule II. 1963 // 1964 // If we have two consecutive control edges where we decend to a 1965 // subexpression and then pop out merge them. 1966 // 1967 // NOTE: this will be limited later in cases where we add barriers 1968 // to prevent this optimization. 1969 // 1970 // For example: 1971 // 1972 // (1.1 -> 1.1.1) -> (1.1.1 -> 1.2) becomes (1.1 -> 1.2). 1973 if (level1 && level2 && 1974 level1 == level4 && 1975 level2 == level3 && PM.getParentIgnoreParens(level2) == level1) { 1976 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1977 path.erase(NextI); 1978 hasChanges = true; 1979 continue; 1980 } 1981 1982 // Rule III. 1983 // 1984 // Eliminate unnecessary edges where we descend to a subexpression from 1985 // a statement at the same level as our parent. 1986 // 1987 // NOTE: this will be limited later in cases where we add barriers 1988 // to prevent this optimization. 1989 // 1990 // For example: 1991 // 1992 // (1.1 -> 1.1.1) -> (1.1.1 -> X) becomes (1.1 -> X). 1993 // 1994 if (level1 && level2 && level1 == PM.getParentIgnoreParens(level2)) { 1995 PieceI->setEndLocation(PieceNextI->getEndLocation()); 1996 path.erase(NextI); 1997 hasChanges = true; 1998 continue; 1999 } 2000 2001 // Rule IV. 2002 // 2003 // Eliminate unnecessary edges where we ascend from a subexpression to 2004 // a statement at the same level as our parent. 2005 // 2006 // NOTE: this will be limited later in cases where we add barriers 2007 // to prevent this optimization. 2008 // 2009 // For example: 2010 // 2011 // (X -> 1.1.1) -> (1.1.1 -> 1.1) becomes (X -> 1.1). 2012 // [first edge] (1.1.1 -> 1.1) -> eliminate 2013 // 2014 if (level2 && level4 && level2 == level3 && level4 == PM.getParent(level2)){ 2015 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2016 path.erase(NextI); 2017 hasChanges = true; 2018 continue; 2019 } 2020#if 0 2021 // Rule V. 2022 // 2023 // Replace terminator conditions with terminators when the condition 2024 // itself has no control-flow. 2025 // 2026 // For example: 2027 // 2028 // (X -> condition) -> (condition -> Y) becomes (X -> term) -> (term -> Y) 2029 // [first edge] (condition -> Y) becomes (term -> Y) 2030 // 2031 // This applies to 'if', 'for', 'while', 'do .. while', 'switch'... 2032 // 2033 if (!isBarrier(CFBS, PieceNextI) && 2034 s1End && s1End == s2Start && level2) { 2035 if (isConditionForTerminator(level2, s1End)) { 2036 PathDiagnosticLocation NewLoc(level2, SM, LC); 2037 PieceI->setEndLocation(NewLoc); 2038 PieceNextI->setStartLocation(NewLoc); 2039 CFBS.insert(PieceI); 2040 hasChanges = true; 2041 continue; 2042 } 2043 2044 } 2045#endif 2046 2047 // No changes at this index? Move to the next one. 2048 ++I; 2049 } 2050 2051 // No changes. 2052 return hasChanges; 2053} 2054 2055//===----------------------------------------------------------------------===// 2056// Methods for BugType and subclasses. 2057//===----------------------------------------------------------------------===// 2058BugType::~BugType() { } 2059 2060void BugType::FlushReports(BugReporter &BR) {} 2061 2062void BuiltinBug::anchor() {} 2063 2064//===----------------------------------------------------------------------===// 2065// Methods for BugReport and subclasses. 2066//===----------------------------------------------------------------------===// 2067 2068void BugReport::NodeResolver::anchor() {} 2069 2070void BugReport::addVisitor(BugReporterVisitor* visitor) { 2071 if (!visitor) 2072 return; 2073 2074 llvm::FoldingSetNodeID ID; 2075 visitor->Profile(ID); 2076 void *InsertPos; 2077 2078 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) { 2079 delete visitor; 2080 return; 2081 } 2082 2083 CallbacksSet.InsertNode(visitor, InsertPos); 2084 Callbacks.push_back(visitor); 2085 ++ConfigurationChangeToken; 2086} 2087 2088BugReport::~BugReport() { 2089 for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) { 2090 delete *I; 2091 } 2092 while (!interestingSymbols.empty()) { 2093 popInterestingSymbolsAndRegions(); 2094 } 2095} 2096 2097const Decl *BugReport::getDeclWithIssue() const { 2098 if (DeclWithIssue) 2099 return DeclWithIssue; 2100 2101 const ExplodedNode *N = getErrorNode(); 2102 if (!N) 2103 return 0; 2104 2105 const LocationContext *LC = N->getLocationContext(); 2106 return LC->getCurrentStackFrame()->getDecl(); 2107} 2108 2109void BugReport::Profile(llvm::FoldingSetNodeID& hash) const { 2110 hash.AddPointer(&BT); 2111 hash.AddString(Description); 2112 PathDiagnosticLocation UL = getUniqueingLocation(); 2113 if (UL.isValid()) { 2114 UL.Profile(hash); 2115 } else if (Location.isValid()) { 2116 Location.Profile(hash); 2117 } else { 2118 assert(ErrorNode); 2119 hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode)); 2120 } 2121 2122 for (SmallVectorImpl<SourceRange>::const_iterator I = 2123 Ranges.begin(), E = Ranges.end(); I != E; ++I) { 2124 const SourceRange range = *I; 2125 if (!range.isValid()) 2126 continue; 2127 hash.AddInteger(range.getBegin().getRawEncoding()); 2128 hash.AddInteger(range.getEnd().getRawEncoding()); 2129 } 2130} 2131 2132void BugReport::markInteresting(SymbolRef sym) { 2133 if (!sym) 2134 return; 2135 2136 // If the symbol wasn't already in our set, note a configuration change. 2137 if (getInterestingSymbols().insert(sym).second) 2138 ++ConfigurationChangeToken; 2139 2140 if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym)) 2141 getInterestingRegions().insert(meta->getRegion()); 2142} 2143 2144void BugReport::markInteresting(const MemRegion *R) { 2145 if (!R) 2146 return; 2147 2148 // If the base region wasn't already in our set, note a configuration change. 2149 R = R->getBaseRegion(); 2150 if (getInterestingRegions().insert(R).second) 2151 ++ConfigurationChangeToken; 2152 2153 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2154 getInterestingSymbols().insert(SR->getSymbol()); 2155} 2156 2157void BugReport::markInteresting(SVal V) { 2158 markInteresting(V.getAsRegion()); 2159 markInteresting(V.getAsSymbol()); 2160} 2161 2162void BugReport::markInteresting(const LocationContext *LC) { 2163 if (!LC) 2164 return; 2165 InterestingLocationContexts.insert(LC); 2166} 2167 2168bool BugReport::isInteresting(SVal V) { 2169 return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol()); 2170} 2171 2172bool BugReport::isInteresting(SymbolRef sym) { 2173 if (!sym) 2174 return false; 2175 // We don't currently consider metadata symbols to be interesting 2176 // even if we know their region is interesting. Is that correct behavior? 2177 return getInterestingSymbols().count(sym); 2178} 2179 2180bool BugReport::isInteresting(const MemRegion *R) { 2181 if (!R) 2182 return false; 2183 R = R->getBaseRegion(); 2184 bool b = getInterestingRegions().count(R); 2185 if (b) 2186 return true; 2187 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2188 return getInterestingSymbols().count(SR->getSymbol()); 2189 return false; 2190} 2191 2192bool BugReport::isInteresting(const LocationContext *LC) { 2193 if (!LC) 2194 return false; 2195 return InterestingLocationContexts.count(LC); 2196} 2197 2198void BugReport::lazyInitializeInterestingSets() { 2199 if (interestingSymbols.empty()) { 2200 interestingSymbols.push_back(new Symbols()); 2201 interestingRegions.push_back(new Regions()); 2202 } 2203} 2204 2205BugReport::Symbols &BugReport::getInterestingSymbols() { 2206 lazyInitializeInterestingSets(); 2207 return *interestingSymbols.back(); 2208} 2209 2210BugReport::Regions &BugReport::getInterestingRegions() { 2211 lazyInitializeInterestingSets(); 2212 return *interestingRegions.back(); 2213} 2214 2215void BugReport::pushInterestingSymbolsAndRegions() { 2216 interestingSymbols.push_back(new Symbols(getInterestingSymbols())); 2217 interestingRegions.push_back(new Regions(getInterestingRegions())); 2218} 2219 2220void BugReport::popInterestingSymbolsAndRegions() { 2221 delete interestingSymbols.back(); 2222 interestingSymbols.pop_back(); 2223 delete interestingRegions.back(); 2224 interestingRegions.pop_back(); 2225} 2226 2227const Stmt *BugReport::getStmt() const { 2228 if (!ErrorNode) 2229 return 0; 2230 2231 ProgramPoint ProgP = ErrorNode->getLocation(); 2232 const Stmt *S = NULL; 2233 2234 if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) { 2235 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit(); 2236 if (BE->getBlock() == &Exit) 2237 S = GetPreviousStmt(ErrorNode); 2238 } 2239 if (!S) 2240 S = PathDiagnosticLocation::getStmt(ErrorNode); 2241 2242 return S; 2243} 2244 2245std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator> 2246BugReport::getRanges() { 2247 // If no custom ranges, add the range of the statement corresponding to 2248 // the error node. 2249 if (Ranges.empty()) { 2250 if (const Expr *E = dyn_cast_or_null<Expr>(getStmt())) 2251 addRange(E->getSourceRange()); 2252 else 2253 return std::make_pair(ranges_iterator(), ranges_iterator()); 2254 } 2255 2256 // User-specified absence of range info. 2257 if (Ranges.size() == 1 && !Ranges.begin()->isValid()) 2258 return std::make_pair(ranges_iterator(), ranges_iterator()); 2259 2260 return std::make_pair(Ranges.begin(), Ranges.end()); 2261} 2262 2263PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const { 2264 if (ErrorNode) { 2265 assert(!Location.isValid() && 2266 "Either Location or ErrorNode should be specified but not both."); 2267 return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM); 2268 } else { 2269 assert(Location.isValid()); 2270 return Location; 2271 } 2272 2273 return PathDiagnosticLocation(); 2274} 2275 2276//===----------------------------------------------------------------------===// 2277// Methods for BugReporter and subclasses. 2278//===----------------------------------------------------------------------===// 2279 2280BugReportEquivClass::~BugReportEquivClass() { } 2281GRBugReporter::~GRBugReporter() { } 2282BugReporterData::~BugReporterData() {} 2283 2284ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); } 2285 2286ProgramStateManager& 2287GRBugReporter::getStateManager() { return Eng.getStateManager(); } 2288 2289BugReporter::~BugReporter() { 2290 FlushReports(); 2291 2292 // Free the bug reports we are tracking. 2293 typedef std::vector<BugReportEquivClass *> ContTy; 2294 for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end(); 2295 I != E; ++I) { 2296 delete *I; 2297 } 2298} 2299 2300void BugReporter::FlushReports() { 2301 if (BugTypes.isEmpty()) 2302 return; 2303 2304 // First flush the warnings for each BugType. This may end up creating new 2305 // warnings and new BugTypes. 2306 // FIXME: Only NSErrorChecker needs BugType's FlushReports. 2307 // Turn NSErrorChecker into a proper checker and remove this. 2308 SmallVector<const BugType*, 16> bugTypes; 2309 for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I) 2310 bugTypes.push_back(*I); 2311 for (SmallVector<const BugType*, 16>::iterator 2312 I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I) 2313 const_cast<BugType*>(*I)->FlushReports(*this); 2314 2315 // We need to flush reports in deterministic order to ensure the order 2316 // of the reports is consistent between runs. 2317 typedef std::vector<BugReportEquivClass *> ContVecTy; 2318 for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.end(); 2319 EI != EE; ++EI){ 2320 BugReportEquivClass& EQ = **EI; 2321 FlushReport(EQ); 2322 } 2323 2324 // BugReporter owns and deletes only BugTypes created implicitly through 2325 // EmitBasicReport. 2326 // FIXME: There are leaks from checkers that assume that the BugTypes they 2327 // create will be destroyed by the BugReporter. 2328 for (llvm::StringMap<BugType*>::iterator 2329 I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I) 2330 delete I->second; 2331 2332 // Remove all references to the BugType objects. 2333 BugTypes = F.getEmptySet(); 2334} 2335 2336//===----------------------------------------------------------------------===// 2337// PathDiagnostics generation. 2338//===----------------------------------------------------------------------===// 2339 2340namespace { 2341/// A wrapper around a report graph, which contains only a single path, and its 2342/// node maps. 2343class ReportGraph { 2344public: 2345 InterExplodedGraphMap BackMap; 2346 OwningPtr<ExplodedGraph> Graph; 2347 const ExplodedNode *ErrorNode; 2348 size_t Index; 2349}; 2350 2351/// A wrapper around a trimmed graph and its node maps. 2352class TrimmedGraph { 2353 InterExplodedGraphMap InverseMap; 2354 2355 typedef llvm::DenseMap<const ExplodedNode *, unsigned> PriorityMapTy; 2356 PriorityMapTy PriorityMap; 2357 2358 typedef std::pair<const ExplodedNode *, size_t> NodeIndexPair; 2359 SmallVector<NodeIndexPair, 32> ReportNodes; 2360 2361 OwningPtr<ExplodedGraph> G; 2362 2363 /// A helper class for sorting ExplodedNodes by priority. 2364 template <bool Descending> 2365 class PriorityCompare { 2366 const PriorityMapTy &PriorityMap; 2367 2368 public: 2369 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {} 2370 2371 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const { 2372 PriorityMapTy::const_iterator LI = PriorityMap.find(LHS); 2373 PriorityMapTy::const_iterator RI = PriorityMap.find(RHS); 2374 PriorityMapTy::const_iterator E = PriorityMap.end(); 2375 2376 if (LI == E) 2377 return Descending; 2378 if (RI == E) 2379 return !Descending; 2380 2381 return Descending ? LI->second > RI->second 2382 : LI->second < RI->second; 2383 } 2384 2385 bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const { 2386 return (*this)(LHS.first, RHS.first); 2387 } 2388 }; 2389 2390public: 2391 TrimmedGraph(const ExplodedGraph *OriginalGraph, 2392 ArrayRef<const ExplodedNode *> Nodes); 2393 2394 bool popNextReportGraph(ReportGraph &GraphWrapper); 2395}; 2396} 2397 2398TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph, 2399 ArrayRef<const ExplodedNode *> Nodes) { 2400 // The trimmed graph is created in the body of the constructor to ensure 2401 // that the DenseMaps have been initialized already. 2402 InterExplodedGraphMap ForwardMap; 2403 G.reset(OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap)); 2404 2405 // Find the (first) error node in the trimmed graph. We just need to consult 2406 // the node map which maps from nodes in the original graph to nodes 2407 // in the new graph. 2408 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes; 2409 2410 for (unsigned i = 0, count = Nodes.size(); i < count; ++i) { 2411 if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) { 2412 ReportNodes.push_back(std::make_pair(NewNode, i)); 2413 RemainingNodes.insert(NewNode); 2414 } 2415 } 2416 2417 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph"); 2418 2419 // Perform a forward BFS to find all the shortest paths. 2420 std::queue<const ExplodedNode *> WS; 2421 2422 assert(G->num_roots() == 1); 2423 WS.push(*G->roots_begin()); 2424 unsigned Priority = 0; 2425 2426 while (!WS.empty()) { 2427 const ExplodedNode *Node = WS.front(); 2428 WS.pop(); 2429 2430 PriorityMapTy::iterator PriorityEntry; 2431 bool IsNew; 2432 llvm::tie(PriorityEntry, IsNew) = 2433 PriorityMap.insert(std::make_pair(Node, Priority)); 2434 ++Priority; 2435 2436 if (!IsNew) { 2437 assert(PriorityEntry->second <= Priority); 2438 continue; 2439 } 2440 2441 if (RemainingNodes.erase(Node)) 2442 if (RemainingNodes.empty()) 2443 break; 2444 2445 for (ExplodedNode::const_pred_iterator I = Node->succ_begin(), 2446 E = Node->succ_end(); 2447 I != E; ++I) 2448 WS.push(*I); 2449 } 2450 2451 // Sort the error paths from longest to shortest. 2452 std::sort(ReportNodes.begin(), ReportNodes.end(), 2453 PriorityCompare<true>(PriorityMap)); 2454} 2455 2456bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) { 2457 if (ReportNodes.empty()) 2458 return false; 2459 2460 const ExplodedNode *OrigN; 2461 llvm::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val(); 2462 assert(PriorityMap.find(OrigN) != PriorityMap.end() && 2463 "error node not accessible from root"); 2464 2465 // Create a new graph with a single path. This is the graph 2466 // that will be returned to the caller. 2467 ExplodedGraph *GNew = new ExplodedGraph(); 2468 GraphWrapper.Graph.reset(GNew); 2469 GraphWrapper.BackMap.clear(); 2470 2471 // Now walk from the error node up the BFS path, always taking the 2472 // predeccessor with the lowest number. 2473 ExplodedNode *Succ = 0; 2474 while (true) { 2475 // Create the equivalent node in the new graph with the same state 2476 // and location. 2477 ExplodedNode *NewN = GNew->getNode(OrigN->getLocation(), OrigN->getState(), 2478 OrigN->isSink()); 2479 2480 // Store the mapping to the original node. 2481 InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN); 2482 assert(IMitr != InverseMap.end() && "No mapping to original node."); 2483 GraphWrapper.BackMap[NewN] = IMitr->second; 2484 2485 // Link up the new node with the previous node. 2486 if (Succ) 2487 Succ->addPredecessor(NewN, *GNew); 2488 else 2489 GraphWrapper.ErrorNode = NewN; 2490 2491 Succ = NewN; 2492 2493 // Are we at the final node? 2494 if (OrigN->pred_empty()) { 2495 GNew->addRoot(NewN); 2496 break; 2497 } 2498 2499 // Find the next predeccessor node. We choose the node that is marked 2500 // with the lowest BFS number. 2501 OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(), 2502 PriorityCompare<false>(PriorityMap)); 2503 } 2504 2505 return true; 2506} 2507 2508 2509/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object 2510/// and collapses PathDiagosticPieces that are expanded by macros. 2511static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) { 2512 typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>, 2513 SourceLocation> > MacroStackTy; 2514 2515 typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> > 2516 PiecesTy; 2517 2518 MacroStackTy MacroStack; 2519 PiecesTy Pieces; 2520 2521 for (PathPieces::const_iterator I = path.begin(), E = path.end(); 2522 I!=E; ++I) { 2523 2524 PathDiagnosticPiece *piece = I->getPtr(); 2525 2526 // Recursively compact calls. 2527 if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){ 2528 CompactPathDiagnostic(call->path, SM); 2529 } 2530 2531 // Get the location of the PathDiagnosticPiece. 2532 const FullSourceLoc Loc = piece->getLocation().asLocation(); 2533 2534 // Determine the instantiation location, which is the location we group 2535 // related PathDiagnosticPieces. 2536 SourceLocation InstantiationLoc = Loc.isMacroID() ? 2537 SM.getExpansionLoc(Loc) : 2538 SourceLocation(); 2539 2540 if (Loc.isFileID()) { 2541 MacroStack.clear(); 2542 Pieces.push_back(piece); 2543 continue; 2544 } 2545 2546 assert(Loc.isMacroID()); 2547 2548 // Is the PathDiagnosticPiece within the same macro group? 2549 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) { 2550 MacroStack.back().first->subPieces.push_back(piece); 2551 continue; 2552 } 2553 2554 // We aren't in the same group. Are we descending into a new macro 2555 // or are part of an old one? 2556 IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup; 2557 2558 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ? 2559 SM.getExpansionLoc(Loc) : 2560 SourceLocation(); 2561 2562 // Walk the entire macro stack. 2563 while (!MacroStack.empty()) { 2564 if (InstantiationLoc == MacroStack.back().second) { 2565 MacroGroup = MacroStack.back().first; 2566 break; 2567 } 2568 2569 if (ParentInstantiationLoc == MacroStack.back().second) { 2570 MacroGroup = MacroStack.back().first; 2571 break; 2572 } 2573 2574 MacroStack.pop_back(); 2575 } 2576 2577 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) { 2578 // Create a new macro group and add it to the stack. 2579 PathDiagnosticMacroPiece *NewGroup = 2580 new PathDiagnosticMacroPiece( 2581 PathDiagnosticLocation::createSingleLocation(piece->getLocation())); 2582 2583 if (MacroGroup) 2584 MacroGroup->subPieces.push_back(NewGroup); 2585 else { 2586 assert(InstantiationLoc.isFileID()); 2587 Pieces.push_back(NewGroup); 2588 } 2589 2590 MacroGroup = NewGroup; 2591 MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc)); 2592 } 2593 2594 // Finally, add the PathDiagnosticPiece to the group. 2595 MacroGroup->subPieces.push_back(piece); 2596 } 2597 2598 // Now take the pieces and construct a new PathDiagnostic. 2599 path.clear(); 2600 2601 for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I) 2602 path.push_back(*I); 2603} 2604 2605bool GRBugReporter::generatePathDiagnostic(PathDiagnostic& PD, 2606 PathDiagnosticConsumer &PC, 2607 ArrayRef<BugReport *> &bugReports) { 2608 assert(!bugReports.empty()); 2609 2610 bool HasValid = false; 2611 bool HasInvalid = false; 2612 SmallVector<const ExplodedNode *, 32> errorNodes; 2613 for (ArrayRef<BugReport*>::iterator I = bugReports.begin(), 2614 E = bugReports.end(); I != E; ++I) { 2615 if ((*I)->isValid()) { 2616 HasValid = true; 2617 errorNodes.push_back((*I)->getErrorNode()); 2618 } else { 2619 // Keep the errorNodes list in sync with the bugReports list. 2620 HasInvalid = true; 2621 errorNodes.push_back(0); 2622 } 2623 } 2624 2625 // If all the reports have been marked invalid by a previous path generation, 2626 // we're done. 2627 if (!HasValid) 2628 return false; 2629 2630 typedef PathDiagnosticConsumer::PathGenerationScheme PathGenerationScheme; 2631 PathGenerationScheme ActiveScheme = PC.getGenerationScheme(); 2632 2633 if (ActiveScheme == PathDiagnosticConsumer::Extensive) { 2634 AnalyzerOptions &options = getEngine().getAnalysisManager().options; 2635 if (options.getBooleanOption("path-diagnostics-alternate", false)) { 2636 ActiveScheme = PathDiagnosticConsumer::AlternateExtensive; 2637 } 2638 } 2639 2640 TrimmedGraph TrimG(&getGraph(), errorNodes); 2641 ReportGraph ErrorGraph; 2642 2643 while (TrimG.popNextReportGraph(ErrorGraph)) { 2644 // Find the BugReport with the original location. 2645 assert(ErrorGraph.Index < bugReports.size()); 2646 BugReport *R = bugReports[ErrorGraph.Index]; 2647 assert(R && "No original report found for sliced graph."); 2648 assert(R->isValid() && "Report selected by trimmed graph marked invalid."); 2649 2650 // Start building the path diagnostic... 2651 PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, &PC); 2652 const ExplodedNode *N = ErrorGraph.ErrorNode; 2653 2654 // Register additional node visitors. 2655 R->addVisitor(new NilReceiverBRVisitor()); 2656 R->addVisitor(new ConditionBRVisitor()); 2657 R->addVisitor(new LikelyFalsePositiveSuppressionBRVisitor()); 2658 2659 BugReport::VisitorList visitors; 2660 unsigned origReportConfigToken, finalReportConfigToken; 2661 LocationContextMap LCM; 2662 2663 // While generating diagnostics, it's possible the visitors will decide 2664 // new symbols and regions are interesting, or add other visitors based on 2665 // the information they find. If they do, we need to regenerate the path 2666 // based on our new report configuration. 2667 do { 2668 // Get a clean copy of all the visitors. 2669 for (BugReport::visitor_iterator I = R->visitor_begin(), 2670 E = R->visitor_end(); I != E; ++I) 2671 visitors.push_back((*I)->clone()); 2672 2673 // Clear out the active path from any previous work. 2674 PD.resetPath(); 2675 origReportConfigToken = R->getConfigurationChangeToken(); 2676 2677 // Generate the very last diagnostic piece - the piece is visible before 2678 // the trace is expanded. 2679 PathDiagnosticPiece *LastPiece = 0; 2680 for (BugReport::visitor_iterator I = visitors.begin(), E = visitors.end(); 2681 I != E; ++I) { 2682 if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) { 2683 assert (!LastPiece && 2684 "There can only be one final piece in a diagnostic."); 2685 LastPiece = Piece; 2686 } 2687 } 2688 2689 if (ActiveScheme != PathDiagnosticConsumer::None) { 2690 if (!LastPiece) 2691 LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R); 2692 assert(LastPiece); 2693 PD.setEndOfPath(LastPiece); 2694 } 2695 2696 // Make sure we get a clean location context map so we don't 2697 // hold onto old mappings. 2698 LCM.clear(); 2699 2700 switch (ActiveScheme) { 2701 case PathDiagnosticConsumer::AlternateExtensive: 2702 GenerateAlternateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 2703 break; 2704 case PathDiagnosticConsumer::Extensive: 2705 GenerateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 2706 break; 2707 case PathDiagnosticConsumer::Minimal: 2708 GenerateMinimalPathDiagnostic(PD, PDB, N, LCM, visitors); 2709 break; 2710 case PathDiagnosticConsumer::None: 2711 GenerateVisitorsOnlyPathDiagnostic(PD, PDB, N, visitors); 2712 break; 2713 } 2714 2715 // Clean up the visitors we used. 2716 llvm::DeleteContainerPointers(visitors); 2717 2718 // Did anything change while generating this path? 2719 finalReportConfigToken = R->getConfigurationChangeToken(); 2720 } while (finalReportConfigToken != origReportConfigToken); 2721 2722 if (!R->isValid()) 2723 continue; 2724 2725 // Finally, prune the diagnostic path of uninteresting stuff. 2726 if (!PD.path.empty()) { 2727 // Remove messages that are basically the same. 2728 removeRedundantMsgs(PD.getMutablePieces()); 2729 2730 if (R->shouldPrunePath() && 2731 getEngine().getAnalysisManager().options.shouldPrunePaths()) { 2732 bool stillHasNotes = removeUnneededCalls(PD.getMutablePieces(), R, LCM); 2733 assert(stillHasNotes); 2734 (void)stillHasNotes; 2735 } 2736 2737 adjustCallLocations(PD.getMutablePieces()); 2738 2739 if (ActiveScheme == PathDiagnosticConsumer::AlternateExtensive) { 2740 ControlFlowBarrierSet CFBS; 2741 OptimizedCallsSet OCS; 2742 while (optimizeEdges(PD.getMutablePieces(), getSourceManager(), CFBS, 2743 OCS, LCM)) {} 2744 } 2745 } 2746 2747 // We found a report and didn't suppress it. 2748 return true; 2749 } 2750 2751 // We suppressed all the reports in this equivalence class. 2752 assert(!HasInvalid && "Inconsistent suppression"); 2753 (void)HasInvalid; 2754 return false; 2755} 2756 2757void BugReporter::Register(BugType *BT) { 2758 BugTypes = F.add(BugTypes, BT); 2759} 2760 2761void BugReporter::emitReport(BugReport* R) { 2762 // Compute the bug report's hash to determine its equivalence class. 2763 llvm::FoldingSetNodeID ID; 2764 R->Profile(ID); 2765 2766 // Lookup the equivance class. If there isn't one, create it. 2767 BugType& BT = R->getBugType(); 2768 Register(&BT); 2769 void *InsertPos; 2770 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos); 2771 2772 if (!EQ) { 2773 EQ = new BugReportEquivClass(R); 2774 EQClasses.InsertNode(EQ, InsertPos); 2775 EQClassesVector.push_back(EQ); 2776 } 2777 else 2778 EQ->AddReport(R); 2779} 2780 2781 2782//===----------------------------------------------------------------------===// 2783// Emitting reports in equivalence classes. 2784//===----------------------------------------------------------------------===// 2785 2786namespace { 2787struct FRIEC_WLItem { 2788 const ExplodedNode *N; 2789 ExplodedNode::const_succ_iterator I, E; 2790 2791 FRIEC_WLItem(const ExplodedNode *n) 2792 : N(n), I(N->succ_begin()), E(N->succ_end()) {} 2793}; 2794} 2795 2796static BugReport * 2797FindReportInEquivalenceClass(BugReportEquivClass& EQ, 2798 SmallVectorImpl<BugReport*> &bugReports) { 2799 2800 BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end(); 2801 assert(I != E); 2802 BugType& BT = I->getBugType(); 2803 2804 // If we don't need to suppress any of the nodes because they are 2805 // post-dominated by a sink, simply add all the nodes in the equivalence class 2806 // to 'Nodes'. Any of the reports will serve as a "representative" report. 2807 if (!BT.isSuppressOnSink()) { 2808 BugReport *R = I; 2809 for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) { 2810 const ExplodedNode *N = I->getErrorNode(); 2811 if (N) { 2812 R = I; 2813 bugReports.push_back(R); 2814 } 2815 } 2816 return R; 2817 } 2818 2819 // For bug reports that should be suppressed when all paths are post-dominated 2820 // by a sink node, iterate through the reports in the equivalence class 2821 // until we find one that isn't post-dominated (if one exists). We use a 2822 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write 2823 // this as a recursive function, but we don't want to risk blowing out the 2824 // stack for very long paths. 2825 BugReport *exampleReport = 0; 2826 2827 for (; I != E; ++I) { 2828 const ExplodedNode *errorNode = I->getErrorNode(); 2829 2830 if (!errorNode) 2831 continue; 2832 if (errorNode->isSink()) { 2833 llvm_unreachable( 2834 "BugType::isSuppressSink() should not be 'true' for sink end nodes"); 2835 } 2836 // No successors? By definition this nodes isn't post-dominated by a sink. 2837 if (errorNode->succ_empty()) { 2838 bugReports.push_back(I); 2839 if (!exampleReport) 2840 exampleReport = I; 2841 continue; 2842 } 2843 2844 // At this point we know that 'N' is not a sink and it has at least one 2845 // successor. Use a DFS worklist to find a non-sink end-of-path node. 2846 typedef FRIEC_WLItem WLItem; 2847 typedef SmallVector<WLItem, 10> DFSWorkList; 2848 llvm::DenseMap<const ExplodedNode *, unsigned> Visited; 2849 2850 DFSWorkList WL; 2851 WL.push_back(errorNode); 2852 Visited[errorNode] = 1; 2853 2854 while (!WL.empty()) { 2855 WLItem &WI = WL.back(); 2856 assert(!WI.N->succ_empty()); 2857 2858 for (; WI.I != WI.E; ++WI.I) { 2859 const ExplodedNode *Succ = *WI.I; 2860 // End-of-path node? 2861 if (Succ->succ_empty()) { 2862 // If we found an end-of-path node that is not a sink. 2863 if (!Succ->isSink()) { 2864 bugReports.push_back(I); 2865 if (!exampleReport) 2866 exampleReport = I; 2867 WL.clear(); 2868 break; 2869 } 2870 // Found a sink? Continue on to the next successor. 2871 continue; 2872 } 2873 // Mark the successor as visited. If it hasn't been explored, 2874 // enqueue it to the DFS worklist. 2875 unsigned &mark = Visited[Succ]; 2876 if (!mark) { 2877 mark = 1; 2878 WL.push_back(Succ); 2879 break; 2880 } 2881 } 2882 2883 // The worklist may have been cleared at this point. First 2884 // check if it is empty before checking the last item. 2885 if (!WL.empty() && &WL.back() == &WI) 2886 WL.pop_back(); 2887 } 2888 } 2889 2890 // ExampleReport will be NULL if all the nodes in the equivalence class 2891 // were post-dominated by sinks. 2892 return exampleReport; 2893} 2894 2895void BugReporter::FlushReport(BugReportEquivClass& EQ) { 2896 SmallVector<BugReport*, 10> bugReports; 2897 BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports); 2898 if (exampleReport) { 2899 const PathDiagnosticConsumers &C = getPathDiagnosticConsumers(); 2900 for (PathDiagnosticConsumers::const_iterator I=C.begin(), 2901 E=C.end(); I != E; ++I) { 2902 FlushReport(exampleReport, **I, bugReports); 2903 } 2904 } 2905} 2906 2907void BugReporter::FlushReport(BugReport *exampleReport, 2908 PathDiagnosticConsumer &PD, 2909 ArrayRef<BugReport*> bugReports) { 2910 2911 // FIXME: Make sure we use the 'R' for the path that was actually used. 2912 // Probably doesn't make a difference in practice. 2913 BugType& BT = exampleReport->getBugType(); 2914 2915 OwningPtr<PathDiagnostic> 2916 D(new PathDiagnostic(exampleReport->getDeclWithIssue(), 2917 exampleReport->getBugType().getName(), 2918 exampleReport->getDescription(), 2919 exampleReport->getShortDescription(/*Fallback=*/false), 2920 BT.getCategory(), 2921 exampleReport->getUniqueingLocation(), 2922 exampleReport->getUniqueingDecl())); 2923 2924 MaxBugClassSize = std::max(bugReports.size(), 2925 static_cast<size_t>(MaxBugClassSize)); 2926 2927 // Generate the full path diagnostic, using the generation scheme 2928 // specified by the PathDiagnosticConsumer. Note that we have to generate 2929 // path diagnostics even for consumers which do not support paths, because 2930 // the BugReporterVisitors may mark this bug as a false positive. 2931 if (!bugReports.empty()) 2932 if (!generatePathDiagnostic(*D.get(), PD, bugReports)) 2933 return; 2934 2935 MaxValidBugClassSize = std::max(bugReports.size(), 2936 static_cast<size_t>(MaxValidBugClassSize)); 2937 2938 // If the path is empty, generate a single step path with the location 2939 // of the issue. 2940 if (D->path.empty()) { 2941 PathDiagnosticLocation L = exampleReport->getLocation(getSourceManager()); 2942 PathDiagnosticPiece *piece = 2943 new PathDiagnosticEventPiece(L, exampleReport->getDescription()); 2944 BugReport::ranges_iterator Beg, End; 2945 llvm::tie(Beg, End) = exampleReport->getRanges(); 2946 for ( ; Beg != End; ++Beg) 2947 piece->addRange(*Beg); 2948 D->setEndOfPath(piece); 2949 } 2950 2951 // Get the meta data. 2952 const BugReport::ExtraTextList &Meta = exampleReport->getExtraText(); 2953 for (BugReport::ExtraTextList::const_iterator i = Meta.begin(), 2954 e = Meta.end(); i != e; ++i) { 2955 D->addMeta(*i); 2956 } 2957 2958 PD.HandlePathDiagnostic(D.take()); 2959} 2960 2961void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, 2962 StringRef name, 2963 StringRef category, 2964 StringRef str, PathDiagnosticLocation Loc, 2965 SourceRange* RBeg, unsigned NumRanges) { 2966 2967 // 'BT' is owned by BugReporter. 2968 BugType *BT = getBugTypeForName(name, category); 2969 BugReport *R = new BugReport(*BT, str, Loc); 2970 R->setDeclWithIssue(DeclWithIssue); 2971 for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg); 2972 emitReport(R); 2973} 2974 2975BugType *BugReporter::getBugTypeForName(StringRef name, 2976 StringRef category) { 2977 SmallString<136> fullDesc; 2978 llvm::raw_svector_ostream(fullDesc) << name << ":" << category; 2979 llvm::StringMapEntry<BugType *> & 2980 entry = StrBugTypes.GetOrCreateValue(fullDesc); 2981 BugType *BT = entry.getValue(); 2982 if (!BT) { 2983 BT = new BugType(name, category); 2984 entry.setValue(BT); 2985 } 2986 return BT; 2987} 2988