BugReporter.cpp revision cff15128c6c089bd6fae841b80680e6f5afbf0bf
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/ExprCXX.h" 22#include "clang/AST/ParentMap.h" 23#include "clang/AST/StmtObjC.h" 24#include "clang/AST/StmtCXX.h" 25#include "clang/Analysis/CFG.h" 26#include "clang/Analysis/ProgramPoint.h" 27#include "clang/Basic/SourceManager.h" 28#include "clang/StaticAnalyzer/Core/BugReporter/BugType.h" 29#include "clang/StaticAnalyzer/Core/BugReporter/PathDiagnostic.h" 30#include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 31#include "llvm/ADT/DenseMap.h" 32#include "llvm/ADT/IntrusiveRefCntPtr.h" 33#include "llvm/ADT/OwningPtr.h" 34#include "llvm/ADT/STLExtras.h" 35#include "llvm/ADT/SmallString.h" 36#include "llvm/ADT/Statistic.h" 37#include "llvm/Support/raw_ostream.h" 38#include <queue> 39 40using namespace clang; 41using namespace ento; 42 43STATISTIC(MaxBugClassSize, 44 "The maximum number of bug reports in the same equivalence class"); 45STATISTIC(MaxValidBugClassSize, 46 "The maximum number of bug reports in the same equivalence class " 47 "where at least one report is valid (not suppressed)"); 48 49BugReporterVisitor::~BugReporterVisitor() {} 50 51void BugReporterContext::anchor() {} 52 53//===----------------------------------------------------------------------===// 54// Helper routines for walking the ExplodedGraph and fetching statements. 55//===----------------------------------------------------------------------===// 56 57static const Stmt *GetPreviousStmt(const ExplodedNode *N) { 58 for (N = N->getFirstPred(); N; N = N->getFirstPred()) 59 if (const Stmt *S = PathDiagnosticLocation::getStmt(N)) 60 return S; 61 62 return 0; 63} 64 65static inline const Stmt* 66GetCurrentOrPreviousStmt(const ExplodedNode *N) { 67 if (const Stmt *S = PathDiagnosticLocation::getStmt(N)) 68 return S; 69 70 return GetPreviousStmt(N); 71} 72 73//===----------------------------------------------------------------------===// 74// Diagnostic cleanup. 75//===----------------------------------------------------------------------===// 76 77static PathDiagnosticEventPiece * 78eventsDescribeSameCondition(PathDiagnosticEventPiece *X, 79 PathDiagnosticEventPiece *Y) { 80 // Prefer diagnostics that come from ConditionBRVisitor over 81 // those that came from TrackConstraintBRVisitor. 82 const void *tagPreferred = ConditionBRVisitor::getTag(); 83 const void *tagLesser = TrackConstraintBRVisitor::getTag(); 84 85 if (X->getLocation() != Y->getLocation()) 86 return 0; 87 88 if (X->getTag() == tagPreferred && Y->getTag() == tagLesser) 89 return X; 90 91 if (Y->getTag() == tagPreferred && X->getTag() == tagLesser) 92 return Y; 93 94 return 0; 95} 96 97/// An optimization pass over PathPieces that removes redundant diagnostics 98/// generated by both ConditionBRVisitor and TrackConstraintBRVisitor. Both 99/// BugReporterVisitors use different methods to generate diagnostics, with 100/// one capable of emitting diagnostics in some cases but not in others. This 101/// can lead to redundant diagnostic pieces at the same point in a path. 102static void removeRedundantMsgs(PathPieces &path) { 103 unsigned N = path.size(); 104 if (N < 2) 105 return; 106 // NOTE: this loop intentionally is not using an iterator. Instead, we 107 // are streaming the path and modifying it in place. This is done by 108 // grabbing the front, processing it, and if we decide to keep it append 109 // it to the end of the path. The entire path is processed in this way. 110 for (unsigned i = 0; i < N; ++i) { 111 IntrusiveRefCntPtr<PathDiagnosticPiece> piece(path.front()); 112 path.pop_front(); 113 114 switch (piece->getKind()) { 115 case clang::ento::PathDiagnosticPiece::Call: 116 removeRedundantMsgs(cast<PathDiagnosticCallPiece>(piece)->path); 117 break; 118 case clang::ento::PathDiagnosticPiece::Macro: 119 removeRedundantMsgs(cast<PathDiagnosticMacroPiece>(piece)->subPieces); 120 break; 121 case clang::ento::PathDiagnosticPiece::ControlFlow: 122 break; 123 case clang::ento::PathDiagnosticPiece::Event: { 124 if (i == N-1) 125 break; 126 127 if (PathDiagnosticEventPiece *nextEvent = 128 dyn_cast<PathDiagnosticEventPiece>(path.front().getPtr())) { 129 PathDiagnosticEventPiece *event = 130 cast<PathDiagnosticEventPiece>(piece); 131 // Check to see if we should keep one of the two pieces. If we 132 // come up with a preference, record which piece to keep, and consume 133 // another piece from the path. 134 if (PathDiagnosticEventPiece *pieceToKeep = 135 eventsDescribeSameCondition(event, nextEvent)) { 136 piece = pieceToKeep; 137 path.pop_front(); 138 ++i; 139 } 140 } 141 break; 142 } 143 } 144 path.push_back(piece); 145 } 146} 147 148/// A map from PathDiagnosticPiece to the LocationContext of the inlined 149/// function call it represents. 150typedef llvm::DenseMap<const PathPieces *, const LocationContext *> 151 LocationContextMap; 152 153/// Recursively scan through a path and prune out calls and macros pieces 154/// that aren't needed. Return true if afterwards the path contains 155/// "interesting stuff" which means it shouldn't be pruned from the parent path. 156static bool removeUnneededCalls(PathPieces &pieces, BugReport *R, 157 LocationContextMap &LCM) { 158 bool containsSomethingInteresting = false; 159 const unsigned N = pieces.size(); 160 161 for (unsigned i = 0 ; i < N ; ++i) { 162 // Remove the front piece from the path. If it is still something we 163 // want to keep once we are done, we will push it back on the end. 164 IntrusiveRefCntPtr<PathDiagnosticPiece> piece(pieces.front()); 165 pieces.pop_front(); 166 167 switch (piece->getKind()) { 168 case PathDiagnosticPiece::Call: { 169 PathDiagnosticCallPiece *call = cast<PathDiagnosticCallPiece>(piece); 170 // Check if the location context is interesting. 171 assert(LCM.count(&call->path)); 172 if (R->isInteresting(LCM[&call->path])) { 173 containsSomethingInteresting = true; 174 break; 175 } 176 177 if (!removeUnneededCalls(call->path, R, LCM)) 178 continue; 179 180 containsSomethingInteresting = true; 181 break; 182 } 183 case PathDiagnosticPiece::Macro: { 184 PathDiagnosticMacroPiece *macro = cast<PathDiagnosticMacroPiece>(piece); 185 if (!removeUnneededCalls(macro->subPieces, R, LCM)) 186 continue; 187 containsSomethingInteresting = true; 188 break; 189 } 190 case PathDiagnosticPiece::Event: { 191 PathDiagnosticEventPiece *event = cast<PathDiagnosticEventPiece>(piece); 192 193 // We never throw away an event, but we do throw it away wholesale 194 // as part of a path if we throw the entire path away. 195 containsSomethingInteresting |= !event->isPrunable(); 196 break; 197 } 198 case PathDiagnosticPiece::ControlFlow: 199 break; 200 } 201 202 pieces.push_back(piece); 203 } 204 205 return containsSomethingInteresting; 206} 207 208/// Returns true if the given decl has been implicitly given a body, either by 209/// the analyzer or by the compiler proper. 210static bool hasImplicitBody(const Decl *D) { 211 assert(D); 212 return D->isImplicit() || !D->hasBody(); 213} 214 215/// Recursively scan through a path and make sure that all call pieces have 216/// valid locations. 217static void adjustCallLocations(PathPieces &Pieces, 218 PathDiagnosticLocation *LastCallLocation = 0) { 219 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E; ++I) { 220 PathDiagnosticCallPiece *Call = dyn_cast<PathDiagnosticCallPiece>(*I); 221 222 if (!Call) { 223 assert((*I)->getLocation().asLocation().isValid()); 224 continue; 225 } 226 227 if (LastCallLocation) { 228 bool CallerIsImplicit = hasImplicitBody(Call->getCaller()); 229 if (CallerIsImplicit || !Call->callEnter.asLocation().isValid()) 230 Call->callEnter = *LastCallLocation; 231 if (CallerIsImplicit || !Call->callReturn.asLocation().isValid()) 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 !hasImplicitBody(Call->getCallee())) 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/// Remove all pieces with invalid locations as these cannot be serialized. 250/// We might have pieces with invalid locations as a result of inlining Body 251/// Farm generated functions. 252static void removePiecesWithInvalidLocations(PathPieces &Pieces) { 253 for (PathPieces::iterator I = Pieces.begin(), E = Pieces.end(); I != E;) { 254 if (PathDiagnosticCallPiece *C = dyn_cast<PathDiagnosticCallPiece>(*I)) 255 removePiecesWithInvalidLocations(C->path); 256 257 if (PathDiagnosticMacroPiece *M = dyn_cast<PathDiagnosticMacroPiece>(*I)) 258 removePiecesWithInvalidLocations(M->subPieces); 259 260 if (!(*I)->getLocation().isValid() || 261 !(*I)->getLocation().asLocation().isValid()) { 262 I = Pieces.erase(I); 263 continue; 264 } 265 I++; 266 } 267} 268 269//===----------------------------------------------------------------------===// 270// PathDiagnosticBuilder and its associated routines and helper objects. 271//===----------------------------------------------------------------------===// 272 273namespace { 274class NodeMapClosure : public BugReport::NodeResolver { 275 InterExplodedGraphMap &M; 276public: 277 NodeMapClosure(InterExplodedGraphMap &m) : M(m) {} 278 279 const ExplodedNode *getOriginalNode(const ExplodedNode *N) { 280 return M.lookup(N); 281 } 282}; 283 284class PathDiagnosticBuilder : public BugReporterContext { 285 BugReport *R; 286 PathDiagnosticConsumer *PDC; 287 NodeMapClosure NMC; 288public: 289 const LocationContext *LC; 290 291 PathDiagnosticBuilder(GRBugReporter &br, 292 BugReport *r, InterExplodedGraphMap &Backmap, 293 PathDiagnosticConsumer *pdc) 294 : BugReporterContext(br), 295 R(r), PDC(pdc), NMC(Backmap), LC(r->getErrorNode()->getLocationContext()) 296 {} 297 298 PathDiagnosticLocation ExecutionContinues(const ExplodedNode *N); 299 300 PathDiagnosticLocation ExecutionContinues(llvm::raw_string_ostream &os, 301 const ExplodedNode *N); 302 303 BugReport *getBugReport() { return R; } 304 305 Decl const &getCodeDecl() { return R->getErrorNode()->getCodeDecl(); } 306 307 ParentMap& getParentMap() { return LC->getParentMap(); } 308 309 const Stmt *getParent(const Stmt *S) { 310 return getParentMap().getParent(S); 311 } 312 313 virtual NodeMapClosure& getNodeResolver() { return NMC; } 314 315 PathDiagnosticLocation getEnclosingStmtLocation(const Stmt *S); 316 317 PathDiagnosticConsumer::PathGenerationScheme getGenerationScheme() const { 318 return PDC ? PDC->getGenerationScheme() : PathDiagnosticConsumer::Extensive; 319 } 320 321 bool supportsLogicalOpControlFlow() const { 322 return PDC ? PDC->supportsLogicalOpControlFlow() : true; 323 } 324}; 325} // end anonymous namespace 326 327PathDiagnosticLocation 328PathDiagnosticBuilder::ExecutionContinues(const ExplodedNode *N) { 329 if (const Stmt *S = PathDiagnosticLocation::getNextStmt(N)) 330 return PathDiagnosticLocation(S, getSourceManager(), LC); 331 332 return PathDiagnosticLocation::createDeclEnd(N->getLocationContext(), 333 getSourceManager()); 334} 335 336PathDiagnosticLocation 337PathDiagnosticBuilder::ExecutionContinues(llvm::raw_string_ostream &os, 338 const ExplodedNode *N) { 339 340 // Slow, but probably doesn't matter. 341 if (os.str().empty()) 342 os << ' '; 343 344 const PathDiagnosticLocation &Loc = ExecutionContinues(N); 345 346 if (Loc.asStmt()) 347 os << "Execution continues on line " 348 << getSourceManager().getExpansionLineNumber(Loc.asLocation()) 349 << '.'; 350 else { 351 os << "Execution jumps to the end of the "; 352 const Decl *D = N->getLocationContext()->getDecl(); 353 if (isa<ObjCMethodDecl>(D)) 354 os << "method"; 355 else if (isa<FunctionDecl>(D)) 356 os << "function"; 357 else { 358 assert(isa<BlockDecl>(D)); 359 os << "anonymous block"; 360 } 361 os << '.'; 362 } 363 364 return Loc; 365} 366 367static const Stmt *getEnclosingParent(const Stmt *S, const ParentMap &PM) { 368 if (isa<Expr>(S) && PM.isConsumedExpr(cast<Expr>(S))) 369 return PM.getParentIgnoreParens(S); 370 371 const Stmt *Parent = PM.getParentIgnoreParens(S); 372 if (!Parent) 373 return 0; 374 375 switch (Parent->getStmtClass()) { 376 case Stmt::ForStmtClass: 377 case Stmt::DoStmtClass: 378 case Stmt::WhileStmtClass: 379 case Stmt::ObjCForCollectionStmtClass: 380 case Stmt::CXXForRangeStmtClass: 381 return Parent; 382 default: 383 break; 384 } 385 386 return 0; 387} 388 389static PathDiagnosticLocation 390getEnclosingStmtLocation(const Stmt *S, SourceManager &SMgr, const ParentMap &P, 391 const LocationContext *LC, bool allowNestedContexts) { 392 if (!S) 393 return PathDiagnosticLocation(); 394 395 while (const Stmt *Parent = getEnclosingParent(S, P)) { 396 switch (Parent->getStmtClass()) { 397 case Stmt::BinaryOperatorClass: { 398 const BinaryOperator *B = cast<BinaryOperator>(Parent); 399 if (B->isLogicalOp()) 400 return PathDiagnosticLocation(allowNestedContexts ? B : S, SMgr, LC); 401 break; 402 } 403 case Stmt::CompoundStmtClass: 404 case Stmt::StmtExprClass: 405 return PathDiagnosticLocation(S, SMgr, LC); 406 case Stmt::ChooseExprClass: 407 // Similar to '?' if we are referring to condition, just have the edge 408 // point to the entire choose expression. 409 if (allowNestedContexts || cast<ChooseExpr>(Parent)->getCond() == S) 410 return PathDiagnosticLocation(Parent, SMgr, LC); 411 else 412 return PathDiagnosticLocation(S, SMgr, LC); 413 case Stmt::BinaryConditionalOperatorClass: 414 case Stmt::ConditionalOperatorClass: 415 // For '?', if we are referring to condition, just have the edge point 416 // to the entire '?' expression. 417 if (allowNestedContexts || 418 cast<AbstractConditionalOperator>(Parent)->getCond() == S) 419 return PathDiagnosticLocation(Parent, SMgr, LC); 420 else 421 return PathDiagnosticLocation(S, SMgr, LC); 422 case Stmt::CXXForRangeStmtClass: 423 if (cast<CXXForRangeStmt>(Parent)->getBody() == S) 424 return PathDiagnosticLocation(S, SMgr, LC); 425 break; 426 case Stmt::DoStmtClass: 427 return PathDiagnosticLocation(S, SMgr, LC); 428 case Stmt::ForStmtClass: 429 if (cast<ForStmt>(Parent)->getBody() == S) 430 return PathDiagnosticLocation(S, SMgr, LC); 431 break; 432 case Stmt::IfStmtClass: 433 if (cast<IfStmt>(Parent)->getCond() != S) 434 return PathDiagnosticLocation(S, SMgr, LC); 435 break; 436 case Stmt::ObjCForCollectionStmtClass: 437 if (cast<ObjCForCollectionStmt>(Parent)->getBody() == S) 438 return PathDiagnosticLocation(S, SMgr, LC); 439 break; 440 case Stmt::WhileStmtClass: 441 if (cast<WhileStmt>(Parent)->getCond() != S) 442 return PathDiagnosticLocation(S, SMgr, LC); 443 break; 444 default: 445 break; 446 } 447 448 S = Parent; 449 } 450 451 assert(S && "Cannot have null Stmt for PathDiagnosticLocation"); 452 453 return PathDiagnosticLocation(S, SMgr, LC); 454} 455 456PathDiagnosticLocation 457PathDiagnosticBuilder::getEnclosingStmtLocation(const Stmt *S) { 458 assert(S && "Null Stmt passed to getEnclosingStmtLocation"); 459 return ::getEnclosingStmtLocation(S, getSourceManager(), getParentMap(), LC, 460 /*allowNestedContexts=*/false); 461} 462 463//===----------------------------------------------------------------------===// 464// "Visitors only" path diagnostic generation algorithm. 465//===----------------------------------------------------------------------===// 466static bool GenerateVisitorsOnlyPathDiagnostic(PathDiagnostic &PD, 467 PathDiagnosticBuilder &PDB, 468 const ExplodedNode *N, 469 ArrayRef<BugReporterVisitor *> visitors) { 470 // All path generation skips the very first node (the error node). 471 // This is because there is special handling for the end-of-path note. 472 N = N->getFirstPred(); 473 if (!N) 474 return true; 475 476 BugReport *R = PDB.getBugReport(); 477 while (const ExplodedNode *Pred = N->getFirstPred()) { 478 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 479 E = visitors.end(); 480 I != E; ++I) { 481 // Visit all the node pairs, but throw the path pieces away. 482 PathDiagnosticPiece *Piece = (*I)->VisitNode(N, Pred, PDB, *R); 483 delete Piece; 484 } 485 486 N = Pred; 487 } 488 489 return R->isValid(); 490} 491 492//===----------------------------------------------------------------------===// 493// "Minimal" path diagnostic generation algorithm. 494//===----------------------------------------------------------------------===// 495typedef std::pair<PathDiagnosticCallPiece*, const ExplodedNode*> StackDiagPair; 496typedef SmallVector<StackDiagPair, 6> StackDiagVector; 497 498static void updateStackPiecesWithMessage(PathDiagnosticPiece *P, 499 StackDiagVector &CallStack) { 500 // If the piece contains a special message, add it to all the call 501 // pieces on the active stack. 502 if (PathDiagnosticEventPiece *ep = 503 dyn_cast<PathDiagnosticEventPiece>(P)) { 504 505 if (ep->hasCallStackHint()) 506 for (StackDiagVector::iterator I = CallStack.begin(), 507 E = CallStack.end(); I != E; ++I) { 508 PathDiagnosticCallPiece *CP = I->first; 509 const ExplodedNode *N = I->second; 510 std::string stackMsg = ep->getCallStackMessage(N); 511 512 // The last message on the path to final bug is the most important 513 // one. Since we traverse the path backwards, do not add the message 514 // if one has been previously added. 515 if (!CP->hasCallStackMessage()) 516 CP->setCallStackMessage(stackMsg); 517 } 518 } 519} 520 521static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM); 522 523static bool GenerateMinimalPathDiagnostic(PathDiagnostic& PD, 524 PathDiagnosticBuilder &PDB, 525 const ExplodedNode *N, 526 LocationContextMap &LCM, 527 ArrayRef<BugReporterVisitor *> visitors) { 528 529 SourceManager& SMgr = PDB.getSourceManager(); 530 const LocationContext *LC = PDB.LC; 531 const ExplodedNode *NextNode = N->pred_empty() 532 ? NULL : *(N->pred_begin()); 533 534 StackDiagVector CallStack; 535 536 while (NextNode) { 537 N = NextNode; 538 PDB.LC = N->getLocationContext(); 539 NextNode = N->getFirstPred(); 540 541 ProgramPoint P = N->getLocation(); 542 543 do { 544 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 545 PathDiagnosticCallPiece *C = 546 PathDiagnosticCallPiece::construct(N, *CE, SMgr); 547 // Record the mapping from call piece to LocationContext. 548 LCM[&C->path] = CE->getCalleeContext(); 549 PD.getActivePath().push_front(C); 550 PD.pushActivePath(&C->path); 551 CallStack.push_back(StackDiagPair(C, N)); 552 break; 553 } 554 555 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 556 // Flush all locations, and pop the active path. 557 bool VisitedEntireCall = PD.isWithinCall(); 558 PD.popActivePath(); 559 560 // Either we just added a bunch of stuff to the top-level path, or 561 // we have a previous CallExitEnd. If the former, it means that the 562 // path terminated within a function call. We must then take the 563 // current contents of the active path and place it within 564 // a new PathDiagnosticCallPiece. 565 PathDiagnosticCallPiece *C; 566 if (VisitedEntireCall) { 567 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 568 } else { 569 const Decl *Caller = CE->getLocationContext()->getDecl(); 570 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 571 // Record the mapping from call piece to LocationContext. 572 LCM[&C->path] = CE->getCalleeContext(); 573 } 574 575 C->setCallee(*CE, SMgr); 576 if (!CallStack.empty()) { 577 assert(CallStack.back().first == C); 578 CallStack.pop_back(); 579 } 580 break; 581 } 582 583 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 584 const CFGBlock *Src = BE->getSrc(); 585 const CFGBlock *Dst = BE->getDst(); 586 const Stmt *T = Src->getTerminator(); 587 588 if (!T) 589 break; 590 591 PathDiagnosticLocation Start = 592 PathDiagnosticLocation::createBegin(T, SMgr, 593 N->getLocationContext()); 594 595 switch (T->getStmtClass()) { 596 default: 597 break; 598 599 case Stmt::GotoStmtClass: 600 case Stmt::IndirectGotoStmtClass: { 601 const Stmt *S = PathDiagnosticLocation::getNextStmt(N); 602 603 if (!S) 604 break; 605 606 std::string sbuf; 607 llvm::raw_string_ostream os(sbuf); 608 const PathDiagnosticLocation &End = PDB.getEnclosingStmtLocation(S); 609 610 os << "Control jumps to line " 611 << End.asLocation().getExpansionLineNumber(); 612 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 613 Start, End, os.str())); 614 break; 615 } 616 617 case Stmt::SwitchStmtClass: { 618 // Figure out what case arm we took. 619 std::string sbuf; 620 llvm::raw_string_ostream os(sbuf); 621 622 if (const Stmt *S = Dst->getLabel()) { 623 PathDiagnosticLocation End(S, SMgr, LC); 624 625 switch (S->getStmtClass()) { 626 default: 627 os << "No cases match in the switch statement. " 628 "Control jumps to line " 629 << End.asLocation().getExpansionLineNumber(); 630 break; 631 case Stmt::DefaultStmtClass: 632 os << "Control jumps to the 'default' case at line " 633 << End.asLocation().getExpansionLineNumber(); 634 break; 635 636 case Stmt::CaseStmtClass: { 637 os << "Control jumps to 'case "; 638 const CaseStmt *Case = cast<CaseStmt>(S); 639 const Expr *LHS = Case->getLHS()->IgnoreParenCasts(); 640 641 // Determine if it is an enum. 642 bool GetRawInt = true; 643 644 if (const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(LHS)) { 645 // FIXME: Maybe this should be an assertion. Are there cases 646 // were it is not an EnumConstantDecl? 647 const EnumConstantDecl *D = 648 dyn_cast<EnumConstantDecl>(DR->getDecl()); 649 650 if (D) { 651 GetRawInt = false; 652 os << *D; 653 } 654 } 655 656 if (GetRawInt) 657 os << LHS->EvaluateKnownConstInt(PDB.getASTContext()); 658 659 os << ":' at line " 660 << End.asLocation().getExpansionLineNumber(); 661 break; 662 } 663 } 664 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 665 Start, End, os.str())); 666 } 667 else { 668 os << "'Default' branch taken. "; 669 const PathDiagnosticLocation &End = PDB.ExecutionContinues(os, N); 670 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 671 Start, End, os.str())); 672 } 673 674 break; 675 } 676 677 case Stmt::BreakStmtClass: 678 case Stmt::ContinueStmtClass: { 679 std::string sbuf; 680 llvm::raw_string_ostream os(sbuf); 681 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 682 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 683 Start, End, os.str())); 684 break; 685 } 686 687 // Determine control-flow for ternary '?'. 688 case Stmt::BinaryConditionalOperatorClass: 689 case Stmt::ConditionalOperatorClass: { 690 std::string sbuf; 691 llvm::raw_string_ostream os(sbuf); 692 os << "'?' condition is "; 693 694 if (*(Src->succ_begin()+1) == Dst) 695 os << "false"; 696 else 697 os << "true"; 698 699 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 700 701 if (const Stmt *S = End.asStmt()) 702 End = PDB.getEnclosingStmtLocation(S); 703 704 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 705 Start, End, os.str())); 706 break; 707 } 708 709 // Determine control-flow for short-circuited '&&' and '||'. 710 case Stmt::BinaryOperatorClass: { 711 if (!PDB.supportsLogicalOpControlFlow()) 712 break; 713 714 const BinaryOperator *B = cast<BinaryOperator>(T); 715 std::string sbuf; 716 llvm::raw_string_ostream os(sbuf); 717 os << "Left side of '"; 718 719 if (B->getOpcode() == BO_LAnd) { 720 os << "&&" << "' is "; 721 722 if (*(Src->succ_begin()+1) == Dst) { 723 os << "false"; 724 PathDiagnosticLocation End(B->getLHS(), SMgr, LC); 725 PathDiagnosticLocation Start = 726 PathDiagnosticLocation::createOperatorLoc(B, SMgr); 727 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 728 Start, End, os.str())); 729 } 730 else { 731 os << "true"; 732 PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); 733 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 734 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 735 Start, End, os.str())); 736 } 737 } 738 else { 739 assert(B->getOpcode() == BO_LOr); 740 os << "||" << "' is "; 741 742 if (*(Src->succ_begin()+1) == Dst) { 743 os << "false"; 744 PathDiagnosticLocation Start(B->getLHS(), SMgr, LC); 745 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 746 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 747 Start, End, os.str())); 748 } 749 else { 750 os << "true"; 751 PathDiagnosticLocation End(B->getLHS(), SMgr, LC); 752 PathDiagnosticLocation Start = 753 PathDiagnosticLocation::createOperatorLoc(B, SMgr); 754 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 755 Start, End, os.str())); 756 } 757 } 758 759 break; 760 } 761 762 case Stmt::DoStmtClass: { 763 if (*(Src->succ_begin()) == Dst) { 764 std::string sbuf; 765 llvm::raw_string_ostream os(sbuf); 766 767 os << "Loop condition is true. "; 768 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 769 770 if (const Stmt *S = End.asStmt()) 771 End = PDB.getEnclosingStmtLocation(S); 772 773 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 774 Start, End, os.str())); 775 } 776 else { 777 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 778 779 if (const Stmt *S = End.asStmt()) 780 End = PDB.getEnclosingStmtLocation(S); 781 782 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 783 Start, End, "Loop condition is false. Exiting loop")); 784 } 785 786 break; 787 } 788 789 case Stmt::WhileStmtClass: 790 case Stmt::ForStmtClass: { 791 if (*(Src->succ_begin()+1) == Dst) { 792 std::string sbuf; 793 llvm::raw_string_ostream os(sbuf); 794 795 os << "Loop condition is false. "; 796 PathDiagnosticLocation End = PDB.ExecutionContinues(os, N); 797 if (const Stmt *S = End.asStmt()) 798 End = PDB.getEnclosingStmtLocation(S); 799 800 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 801 Start, End, os.str())); 802 } 803 else { 804 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 805 if (const Stmt *S = End.asStmt()) 806 End = PDB.getEnclosingStmtLocation(S); 807 808 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 809 Start, End, "Loop condition is true. Entering loop body")); 810 } 811 812 break; 813 } 814 815 case Stmt::IfStmtClass: { 816 PathDiagnosticLocation End = PDB.ExecutionContinues(N); 817 818 if (const Stmt *S = End.asStmt()) 819 End = PDB.getEnclosingStmtLocation(S); 820 821 if (*(Src->succ_begin()+1) == Dst) 822 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 823 Start, End, "Taking false branch")); 824 else 825 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece( 826 Start, End, "Taking true branch")); 827 828 break; 829 } 830 } 831 } 832 } while(0); 833 834 if (NextNode) { 835 // Add diagnostic pieces from custom visitors. 836 BugReport *R = PDB.getBugReport(); 837 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 838 E = visitors.end(); 839 I != E; ++I) { 840 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 841 PD.getActivePath().push_front(p); 842 updateStackPiecesWithMessage(p, CallStack); 843 } 844 } 845 } 846 } 847 848 if (!PDB.getBugReport()->isValid()) 849 return false; 850 851 // After constructing the full PathDiagnostic, do a pass over it to compact 852 // PathDiagnosticPieces that occur within a macro. 853 CompactPathDiagnostic(PD.getMutablePieces(), PDB.getSourceManager()); 854 return true; 855} 856 857//===----------------------------------------------------------------------===// 858// "Extensive" PathDiagnostic generation. 859//===----------------------------------------------------------------------===// 860 861static bool IsControlFlowExpr(const Stmt *S) { 862 const Expr *E = dyn_cast<Expr>(S); 863 864 if (!E) 865 return false; 866 867 E = E->IgnoreParenCasts(); 868 869 if (isa<AbstractConditionalOperator>(E)) 870 return true; 871 872 if (const BinaryOperator *B = dyn_cast<BinaryOperator>(E)) 873 if (B->isLogicalOp()) 874 return true; 875 876 return false; 877} 878 879namespace { 880class ContextLocation : public PathDiagnosticLocation { 881 bool IsDead; 882public: 883 ContextLocation(const PathDiagnosticLocation &L, bool isdead = false) 884 : PathDiagnosticLocation(L), IsDead(isdead) {} 885 886 void markDead() { IsDead = true; } 887 bool isDead() const { return IsDead; } 888}; 889 890static PathDiagnosticLocation cleanUpLocation(PathDiagnosticLocation L, 891 const LocationContext *LC, 892 bool firstCharOnly = false) { 893 if (const Stmt *S = L.asStmt()) { 894 const Stmt *Original = S; 895 while (1) { 896 // Adjust the location for some expressions that are best referenced 897 // by one of their subexpressions. 898 switch (S->getStmtClass()) { 899 default: 900 break; 901 case Stmt::ParenExprClass: 902 case Stmt::GenericSelectionExprClass: 903 S = cast<Expr>(S)->IgnoreParens(); 904 firstCharOnly = true; 905 continue; 906 case Stmt::BinaryConditionalOperatorClass: 907 case Stmt::ConditionalOperatorClass: 908 S = cast<AbstractConditionalOperator>(S)->getCond(); 909 firstCharOnly = true; 910 continue; 911 case Stmt::ChooseExprClass: 912 S = cast<ChooseExpr>(S)->getCond(); 913 firstCharOnly = true; 914 continue; 915 case Stmt::BinaryOperatorClass: 916 S = cast<BinaryOperator>(S)->getLHS(); 917 firstCharOnly = true; 918 continue; 919 } 920 921 break; 922 } 923 924 if (S != Original) 925 L = PathDiagnosticLocation(S, L.getManager(), LC); 926 } 927 928 if (firstCharOnly) 929 L = PathDiagnosticLocation::createSingleLocation(L); 930 931 return L; 932} 933 934class EdgeBuilder { 935 std::vector<ContextLocation> CLocs; 936 typedef std::vector<ContextLocation>::iterator iterator; 937 PathDiagnostic &PD; 938 PathDiagnosticBuilder &PDB; 939 PathDiagnosticLocation PrevLoc; 940 941 bool IsConsumedExpr(const PathDiagnosticLocation &L); 942 943 bool containsLocation(const PathDiagnosticLocation &Container, 944 const PathDiagnosticLocation &Containee); 945 946 PathDiagnosticLocation getContextLocation(const PathDiagnosticLocation &L); 947 948 949 950 void popLocation() { 951 if (!CLocs.back().isDead() && CLocs.back().asLocation().isFileID()) { 952 // For contexts, we only one the first character as the range. 953 rawAddEdge(cleanUpLocation(CLocs.back(), PDB.LC, true)); 954 } 955 CLocs.pop_back(); 956 } 957 958public: 959 EdgeBuilder(PathDiagnostic &pd, PathDiagnosticBuilder &pdb) 960 : PD(pd), PDB(pdb) { 961 962 // If the PathDiagnostic already has pieces, add the enclosing statement 963 // of the first piece as a context as well. 964 if (!PD.path.empty()) { 965 PrevLoc = (*PD.path.begin())->getLocation(); 966 967 if (const Stmt *S = PrevLoc.asStmt()) 968 addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 969 } 970 } 971 972 ~EdgeBuilder() { 973 while (!CLocs.empty()) popLocation(); 974 975 // Finally, add an initial edge from the start location of the first 976 // statement (if it doesn't already exist). 977 PathDiagnosticLocation L = PathDiagnosticLocation::createDeclBegin( 978 PDB.LC, 979 PDB.getSourceManager()); 980 if (L.isValid()) 981 rawAddEdge(L); 982 } 983 984 void flushLocations() { 985 while (!CLocs.empty()) 986 popLocation(); 987 PrevLoc = PathDiagnosticLocation(); 988 } 989 990 void addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd = false, 991 bool IsPostJump = false); 992 993 void rawAddEdge(PathDiagnosticLocation NewLoc); 994 995 void addContext(const Stmt *S); 996 void addContext(const PathDiagnosticLocation &L); 997 void addExtendedContext(const Stmt *S); 998}; 999} // end anonymous namespace 1000 1001 1002PathDiagnosticLocation 1003EdgeBuilder::getContextLocation(const PathDiagnosticLocation &L) { 1004 if (const Stmt *S = L.asStmt()) { 1005 if (IsControlFlowExpr(S)) 1006 return L; 1007 1008 return PDB.getEnclosingStmtLocation(S); 1009 } 1010 1011 return L; 1012} 1013 1014bool EdgeBuilder::containsLocation(const PathDiagnosticLocation &Container, 1015 const PathDiagnosticLocation &Containee) { 1016 1017 if (Container == Containee) 1018 return true; 1019 1020 if (Container.asDecl()) 1021 return true; 1022 1023 if (const Stmt *S = Containee.asStmt()) 1024 if (const Stmt *ContainerS = Container.asStmt()) { 1025 while (S) { 1026 if (S == ContainerS) 1027 return true; 1028 S = PDB.getParent(S); 1029 } 1030 return false; 1031 } 1032 1033 // Less accurate: compare using source ranges. 1034 SourceRange ContainerR = Container.asRange(); 1035 SourceRange ContaineeR = Containee.asRange(); 1036 1037 SourceManager &SM = PDB.getSourceManager(); 1038 SourceLocation ContainerRBeg = SM.getExpansionLoc(ContainerR.getBegin()); 1039 SourceLocation ContainerREnd = SM.getExpansionLoc(ContainerR.getEnd()); 1040 SourceLocation ContaineeRBeg = SM.getExpansionLoc(ContaineeR.getBegin()); 1041 SourceLocation ContaineeREnd = SM.getExpansionLoc(ContaineeR.getEnd()); 1042 1043 unsigned ContainerBegLine = SM.getExpansionLineNumber(ContainerRBeg); 1044 unsigned ContainerEndLine = SM.getExpansionLineNumber(ContainerREnd); 1045 unsigned ContaineeBegLine = SM.getExpansionLineNumber(ContaineeRBeg); 1046 unsigned ContaineeEndLine = SM.getExpansionLineNumber(ContaineeREnd); 1047 1048 assert(ContainerBegLine <= ContainerEndLine); 1049 assert(ContaineeBegLine <= ContaineeEndLine); 1050 1051 return (ContainerBegLine <= ContaineeBegLine && 1052 ContainerEndLine >= ContaineeEndLine && 1053 (ContainerBegLine != ContaineeBegLine || 1054 SM.getExpansionColumnNumber(ContainerRBeg) <= 1055 SM.getExpansionColumnNumber(ContaineeRBeg)) && 1056 (ContainerEndLine != ContaineeEndLine || 1057 SM.getExpansionColumnNumber(ContainerREnd) >= 1058 SM.getExpansionColumnNumber(ContaineeREnd))); 1059} 1060 1061void EdgeBuilder::rawAddEdge(PathDiagnosticLocation NewLoc) { 1062 if (!PrevLoc.isValid()) { 1063 PrevLoc = NewLoc; 1064 return; 1065 } 1066 1067 const PathDiagnosticLocation &NewLocClean = cleanUpLocation(NewLoc, PDB.LC); 1068 const PathDiagnosticLocation &PrevLocClean = cleanUpLocation(PrevLoc, PDB.LC); 1069 1070 if (PrevLocClean.asLocation().isInvalid()) { 1071 PrevLoc = NewLoc; 1072 return; 1073 } 1074 1075 if (NewLocClean.asLocation() == PrevLocClean.asLocation()) 1076 return; 1077 1078 // FIXME: Ignore intra-macro edges for now. 1079 if (NewLocClean.asLocation().getExpansionLoc() == 1080 PrevLocClean.asLocation().getExpansionLoc()) 1081 return; 1082 1083 PD.getActivePath().push_front(new PathDiagnosticControlFlowPiece(NewLocClean, PrevLocClean)); 1084 PrevLoc = NewLoc; 1085} 1086 1087void EdgeBuilder::addEdge(PathDiagnosticLocation NewLoc, bool alwaysAdd, 1088 bool IsPostJump) { 1089 1090 if (!alwaysAdd && NewLoc.asLocation().isMacroID()) 1091 return; 1092 1093 const PathDiagnosticLocation &CLoc = getContextLocation(NewLoc); 1094 1095 while (!CLocs.empty()) { 1096 ContextLocation &TopContextLoc = CLocs.back(); 1097 1098 // Is the top location context the same as the one for the new location? 1099 if (TopContextLoc == CLoc) { 1100 if (alwaysAdd) { 1101 if (IsConsumedExpr(TopContextLoc)) 1102 TopContextLoc.markDead(); 1103 1104 rawAddEdge(NewLoc); 1105 } 1106 1107 if (IsPostJump) 1108 TopContextLoc.markDead(); 1109 return; 1110 } 1111 1112 if (containsLocation(TopContextLoc, CLoc)) { 1113 if (alwaysAdd) { 1114 rawAddEdge(NewLoc); 1115 1116 if (IsConsumedExpr(CLoc)) { 1117 CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/true)); 1118 return; 1119 } 1120 } 1121 1122 CLocs.push_back(ContextLocation(CLoc, /*IsDead=*/IsPostJump)); 1123 return; 1124 } 1125 1126 // Context does not contain the location. Flush it. 1127 popLocation(); 1128 } 1129 1130 // If we reach here, there is no enclosing context. Just add the edge. 1131 rawAddEdge(NewLoc); 1132} 1133 1134bool EdgeBuilder::IsConsumedExpr(const PathDiagnosticLocation &L) { 1135 if (const Expr *X = dyn_cast_or_null<Expr>(L.asStmt())) 1136 return PDB.getParentMap().isConsumedExpr(X) && !IsControlFlowExpr(X); 1137 1138 return false; 1139} 1140 1141void EdgeBuilder::addExtendedContext(const Stmt *S) { 1142 if (!S) 1143 return; 1144 1145 const Stmt *Parent = PDB.getParent(S); 1146 while (Parent) { 1147 if (isa<CompoundStmt>(Parent)) 1148 Parent = PDB.getParent(Parent); 1149 else 1150 break; 1151 } 1152 1153 if (Parent) { 1154 switch (Parent->getStmtClass()) { 1155 case Stmt::DoStmtClass: 1156 case Stmt::ObjCAtSynchronizedStmtClass: 1157 addContext(Parent); 1158 default: 1159 break; 1160 } 1161 } 1162 1163 addContext(S); 1164} 1165 1166void EdgeBuilder::addContext(const Stmt *S) { 1167 if (!S) 1168 return; 1169 1170 PathDiagnosticLocation L(S, PDB.getSourceManager(), PDB.LC); 1171 addContext(L); 1172} 1173 1174void EdgeBuilder::addContext(const PathDiagnosticLocation &L) { 1175 while (!CLocs.empty()) { 1176 const PathDiagnosticLocation &TopContextLoc = CLocs.back(); 1177 1178 // Is the top location context the same as the one for the new location? 1179 if (TopContextLoc == L) 1180 return; 1181 1182 if (containsLocation(TopContextLoc, L)) { 1183 CLocs.push_back(L); 1184 return; 1185 } 1186 1187 // Context does not contain the location. Flush it. 1188 popLocation(); 1189 } 1190 1191 CLocs.push_back(L); 1192} 1193 1194// Cone-of-influence: support the reverse propagation of "interesting" symbols 1195// and values by tracing interesting calculations backwards through evaluated 1196// expressions along a path. This is probably overly complicated, but the idea 1197// is that if an expression computed an "interesting" value, the child 1198// expressions are are also likely to be "interesting" as well (which then 1199// propagates to the values they in turn compute). This reverse propagation 1200// is needed to track interesting correlations across function call boundaries, 1201// where formal arguments bind to actual arguments, etc. This is also needed 1202// because the constraint solver sometimes simplifies certain symbolic values 1203// into constants when appropriate, and this complicates reasoning about 1204// interesting values. 1205typedef llvm::DenseSet<const Expr *> InterestingExprs; 1206 1207static void reversePropagateIntererstingSymbols(BugReport &R, 1208 InterestingExprs &IE, 1209 const ProgramState *State, 1210 const Expr *Ex, 1211 const LocationContext *LCtx) { 1212 SVal V = State->getSVal(Ex, LCtx); 1213 if (!(R.isInteresting(V) || IE.count(Ex))) 1214 return; 1215 1216 switch (Ex->getStmtClass()) { 1217 default: 1218 if (!isa<CastExpr>(Ex)) 1219 break; 1220 // Fall through. 1221 case Stmt::BinaryOperatorClass: 1222 case Stmt::UnaryOperatorClass: { 1223 for (Stmt::const_child_iterator CI = Ex->child_begin(), 1224 CE = Ex->child_end(); 1225 CI != CE; ++CI) { 1226 if (const Expr *child = dyn_cast_or_null<Expr>(*CI)) { 1227 IE.insert(child); 1228 SVal ChildV = State->getSVal(child, LCtx); 1229 R.markInteresting(ChildV); 1230 } 1231 break; 1232 } 1233 } 1234 } 1235 1236 R.markInteresting(V); 1237} 1238 1239static void reversePropagateInterestingSymbols(BugReport &R, 1240 InterestingExprs &IE, 1241 const ProgramState *State, 1242 const LocationContext *CalleeCtx, 1243 const LocationContext *CallerCtx) 1244{ 1245 // FIXME: Handle non-CallExpr-based CallEvents. 1246 const StackFrameContext *Callee = CalleeCtx->getCurrentStackFrame(); 1247 const Stmt *CallSite = Callee->getCallSite(); 1248 if (const CallExpr *CE = dyn_cast_or_null<CallExpr>(CallSite)) { 1249 if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(CalleeCtx->getDecl())) { 1250 FunctionDecl::param_const_iterator PI = FD->param_begin(), 1251 PE = FD->param_end(); 1252 CallExpr::const_arg_iterator AI = CE->arg_begin(), AE = CE->arg_end(); 1253 for (; AI != AE && PI != PE; ++AI, ++PI) { 1254 if (const Expr *ArgE = *AI) { 1255 if (const ParmVarDecl *PD = *PI) { 1256 Loc LV = State->getLValue(PD, CalleeCtx); 1257 if (R.isInteresting(LV) || R.isInteresting(State->getRawSVal(LV))) 1258 IE.insert(ArgE); 1259 } 1260 } 1261 } 1262 } 1263 } 1264} 1265 1266//===----------------------------------------------------------------------===// 1267// Functions for determining if a loop was executed 0 times. 1268//===----------------------------------------------------------------------===// 1269 1270static bool isLoop(const Stmt *Term) { 1271 switch (Term->getStmtClass()) { 1272 case Stmt::ForStmtClass: 1273 case Stmt::WhileStmtClass: 1274 case Stmt::ObjCForCollectionStmtClass: 1275 case Stmt::CXXForRangeStmtClass: 1276 return true; 1277 default: 1278 // Note that we intentionally do not include do..while here. 1279 return false; 1280 } 1281} 1282 1283static bool isJumpToFalseBranch(const BlockEdge *BE) { 1284 const CFGBlock *Src = BE->getSrc(); 1285 assert(Src->succ_size() == 2); 1286 return (*(Src->succ_begin()+1) == BE->getDst()); 1287} 1288 1289/// Return true if the terminator is a loop and the destination is the 1290/// false branch. 1291static bool isLoopJumpPastBody(const Stmt *Term, const BlockEdge *BE) { 1292 if (!isLoop(Term)) 1293 return false; 1294 1295 // Did we take the false branch? 1296 return isJumpToFalseBranch(BE); 1297} 1298 1299static bool isContainedByStmt(ParentMap &PM, const Stmt *S, const Stmt *SubS) { 1300 while (SubS) { 1301 if (SubS == S) 1302 return true; 1303 SubS = PM.getParent(SubS); 1304 } 1305 return false; 1306} 1307 1308static const Stmt *getStmtBeforeCond(ParentMap &PM, const Stmt *Term, 1309 const ExplodedNode *N) { 1310 while (N) { 1311 Optional<StmtPoint> SP = N->getLocation().getAs<StmtPoint>(); 1312 if (SP) { 1313 const Stmt *S = SP->getStmt(); 1314 if (!isContainedByStmt(PM, Term, S)) 1315 return S; 1316 } 1317 N = N->getFirstPred(); 1318 } 1319 return 0; 1320} 1321 1322static bool isInLoopBody(ParentMap &PM, const Stmt *S, const Stmt *Term) { 1323 const Stmt *LoopBody = 0; 1324 switch (Term->getStmtClass()) { 1325 case Stmt::CXXForRangeStmtClass: { 1326 const CXXForRangeStmt *FR = cast<CXXForRangeStmt>(Term); 1327 if (isContainedByStmt(PM, FR->getInc(), S)) 1328 return true; 1329 if (isContainedByStmt(PM, FR->getLoopVarStmt(), S)) 1330 return true; 1331 LoopBody = FR->getBody(); 1332 break; 1333 } 1334 case Stmt::ForStmtClass: { 1335 const ForStmt *FS = cast<ForStmt>(Term); 1336 if (isContainedByStmt(PM, FS->getInc(), S)) 1337 return true; 1338 LoopBody = FS->getBody(); 1339 break; 1340 } 1341 case Stmt::ObjCForCollectionStmtClass: { 1342 const ObjCForCollectionStmt *FC = cast<ObjCForCollectionStmt>(Term); 1343 LoopBody = FC->getBody(); 1344 break; 1345 } 1346 case Stmt::WhileStmtClass: 1347 LoopBody = cast<WhileStmt>(Term)->getBody(); 1348 break; 1349 default: 1350 return false; 1351 } 1352 return isContainedByStmt(PM, LoopBody, S); 1353} 1354 1355//===----------------------------------------------------------------------===// 1356// Top-level logic for generating extensive path diagnostics. 1357//===----------------------------------------------------------------------===// 1358 1359static bool GenerateExtensivePathDiagnostic(PathDiagnostic& PD, 1360 PathDiagnosticBuilder &PDB, 1361 const ExplodedNode *N, 1362 LocationContextMap &LCM, 1363 ArrayRef<BugReporterVisitor *> visitors) { 1364 EdgeBuilder EB(PD, PDB); 1365 const SourceManager& SM = PDB.getSourceManager(); 1366 StackDiagVector CallStack; 1367 InterestingExprs IE; 1368 1369 const ExplodedNode *NextNode = N->pred_empty() ? NULL : *(N->pred_begin()); 1370 while (NextNode) { 1371 N = NextNode; 1372 NextNode = N->getFirstPred(); 1373 ProgramPoint P = N->getLocation(); 1374 1375 do { 1376 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1377 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1378 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1379 N->getState().getPtr(), Ex, 1380 N->getLocationContext()); 1381 } 1382 1383 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1384 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1385 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1386 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1387 N->getState().getPtr(), Ex, 1388 N->getLocationContext()); 1389 } 1390 1391 PathDiagnosticCallPiece *C = 1392 PathDiagnosticCallPiece::construct(N, *CE, SM); 1393 LCM[&C->path] = CE->getCalleeContext(); 1394 1395 EB.addEdge(C->callReturn, /*AlwaysAdd=*/true, /*IsPostJump=*/true); 1396 EB.flushLocations(); 1397 1398 PD.getActivePath().push_front(C); 1399 PD.pushActivePath(&C->path); 1400 CallStack.push_back(StackDiagPair(C, N)); 1401 break; 1402 } 1403 1404 // Pop the call hierarchy if we are done walking the contents 1405 // of a function call. 1406 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1407 // Add an edge to the start of the function. 1408 const Decl *D = CE->getCalleeContext()->getDecl(); 1409 PathDiagnosticLocation pos = 1410 PathDiagnosticLocation::createBegin(D, SM); 1411 EB.addEdge(pos); 1412 1413 // Flush all locations, and pop the active path. 1414 bool VisitedEntireCall = PD.isWithinCall(); 1415 EB.flushLocations(); 1416 PD.popActivePath(); 1417 PDB.LC = N->getLocationContext(); 1418 1419 // Either we just added a bunch of stuff to the top-level path, or 1420 // we have a previous CallExitEnd. If the former, it means that the 1421 // path terminated within a function call. We must then take the 1422 // current contents of the active path and place it within 1423 // a new PathDiagnosticCallPiece. 1424 PathDiagnosticCallPiece *C; 1425 if (VisitedEntireCall) { 1426 C = cast<PathDiagnosticCallPiece>(PD.getActivePath().front()); 1427 } else { 1428 const Decl *Caller = CE->getLocationContext()->getDecl(); 1429 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1430 LCM[&C->path] = CE->getCalleeContext(); 1431 } 1432 1433 C->setCallee(*CE, SM); 1434 EB.addContext(C->getLocation()); 1435 1436 if (!CallStack.empty()) { 1437 assert(CallStack.back().first == C); 1438 CallStack.pop_back(); 1439 } 1440 break; 1441 } 1442 1443 // Note that is important that we update the LocationContext 1444 // after looking at CallExits. CallExit basically adds an 1445 // edge in the *caller*, so we don't want to update the LocationContext 1446 // too soon. 1447 PDB.LC = N->getLocationContext(); 1448 1449 // Block edges. 1450 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1451 // Does this represent entering a call? If so, look at propagating 1452 // interesting symbols across call boundaries. 1453 if (NextNode) { 1454 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1455 const LocationContext *CalleeCtx = PDB.LC; 1456 if (CallerCtx != CalleeCtx) { 1457 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1458 N->getState().getPtr(), 1459 CalleeCtx, CallerCtx); 1460 } 1461 } 1462 1463 // Are we jumping to the head of a loop? Add a special diagnostic. 1464 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1465 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1466 const CompoundStmt *CS = NULL; 1467 1468 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1469 CS = dyn_cast<CompoundStmt>(FS->getBody()); 1470 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1471 CS = dyn_cast<CompoundStmt>(WS->getBody()); 1472 1473 PathDiagnosticEventPiece *p = 1474 new PathDiagnosticEventPiece(L, 1475 "Looping back to the head of the loop"); 1476 p->setPrunable(true); 1477 1478 EB.addEdge(p->getLocation(), true); 1479 PD.getActivePath().push_front(p); 1480 1481 if (CS) { 1482 PathDiagnosticLocation BL = 1483 PathDiagnosticLocation::createEndBrace(CS, SM); 1484 EB.addEdge(BL); 1485 } 1486 } 1487 1488 const CFGBlock *BSrc = BE->getSrc(); 1489 ParentMap &PM = PDB.getParentMap(); 1490 1491 if (const Stmt *Term = BSrc->getTerminator()) { 1492 // Are we jumping past the loop body without ever executing the 1493 // loop (because the condition was false)? 1494 if (isLoopJumpPastBody(Term, &*BE) && 1495 !isInLoopBody(PM, 1496 getStmtBeforeCond(PM, 1497 BSrc->getTerminatorCondition(), 1498 N), 1499 Term)) { 1500 PathDiagnosticLocation L(Term, SM, PDB.LC); 1501 PathDiagnosticEventPiece *PE = 1502 new PathDiagnosticEventPiece(L, "Loop body executed 0 times"); 1503 PE->setPrunable(true); 1504 1505 EB.addEdge(PE->getLocation(), true); 1506 PD.getActivePath().push_front(PE); 1507 } 1508 1509 // In any case, add the terminator as the current statement 1510 // context for control edges. 1511 EB.addContext(Term); 1512 } 1513 1514 break; 1515 } 1516 1517 if (Optional<BlockEntrance> BE = P.getAs<BlockEntrance>()) { 1518 Optional<CFGElement> First = BE->getFirstElement(); 1519 if (Optional<CFGStmt> S = First ? First->getAs<CFGStmt>() : None) { 1520 const Stmt *stmt = S->getStmt(); 1521 if (IsControlFlowExpr(stmt)) { 1522 // Add the proper context for '&&', '||', and '?'. 1523 EB.addContext(stmt); 1524 } 1525 else 1526 EB.addExtendedContext(PDB.getEnclosingStmtLocation(stmt).asStmt()); 1527 } 1528 1529 break; 1530 } 1531 1532 1533 } while (0); 1534 1535 if (!NextNode) 1536 continue; 1537 1538 // Add pieces from custom visitors. 1539 BugReport *R = PDB.getBugReport(); 1540 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1541 E = visitors.end(); 1542 I != E; ++I) { 1543 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *R)) { 1544 const PathDiagnosticLocation &Loc = p->getLocation(); 1545 EB.addEdge(Loc, true); 1546 PD.getActivePath().push_front(p); 1547 updateStackPiecesWithMessage(p, CallStack); 1548 1549 if (const Stmt *S = Loc.asStmt()) 1550 EB.addExtendedContext(PDB.getEnclosingStmtLocation(S).asStmt()); 1551 } 1552 } 1553 } 1554 1555 return PDB.getBugReport()->isValid(); 1556} 1557 1558/// \brief Adds a sanitized control-flow diagnostic edge to a path. 1559static void addEdgeToPath(PathPieces &path, 1560 PathDiagnosticLocation &PrevLoc, 1561 PathDiagnosticLocation NewLoc, 1562 const LocationContext *LC) { 1563 if (!NewLoc.isValid()) 1564 return; 1565 1566 SourceLocation NewLocL = NewLoc.asLocation(); 1567 if (NewLocL.isInvalid()) 1568 return; 1569 1570 if (!PrevLoc.isValid() || !PrevLoc.asLocation().isValid()) { 1571 PrevLoc = NewLoc; 1572 return; 1573 } 1574 1575 // Ignore self-edges, which occur when there are multiple nodes at the same 1576 // statement. 1577 if (NewLoc.asStmt() && NewLoc.asStmt() == PrevLoc.asStmt()) 1578 return; 1579 1580 path.push_front(new PathDiagnosticControlFlowPiece(NewLoc, 1581 PrevLoc)); 1582 PrevLoc = NewLoc; 1583} 1584 1585/// A customized wrapper for CFGBlock::getTerminatorCondition() 1586/// which returns the element for ObjCForCollectionStmts. 1587static const Stmt *getTerminatorCondition(const CFGBlock *B) { 1588 const Stmt *S = B->getTerminatorCondition(); 1589 if (const ObjCForCollectionStmt *FS = 1590 dyn_cast_or_null<ObjCForCollectionStmt>(S)) 1591 return FS->getElement(); 1592 return S; 1593} 1594 1595static const char *StrEnteringLoop = "Entering loop body"; 1596static const char *StrLoopBodyZero = "Loop body executed 0 times"; 1597 1598static bool 1599GenerateAlternateExtensivePathDiagnostic(PathDiagnostic& PD, 1600 PathDiagnosticBuilder &PDB, 1601 const ExplodedNode *N, 1602 LocationContextMap &LCM, 1603 ArrayRef<BugReporterVisitor *> visitors) { 1604 1605 BugReport *report = PDB.getBugReport(); 1606 const SourceManager& SM = PDB.getSourceManager(); 1607 StackDiagVector CallStack; 1608 InterestingExprs IE; 1609 1610 PathDiagnosticLocation PrevLoc = PD.getLocation(); 1611 1612 const ExplodedNode *NextNode = N->getFirstPred(); 1613 while (NextNode) { 1614 N = NextNode; 1615 NextNode = N->getFirstPred(); 1616 ProgramPoint P = N->getLocation(); 1617 1618 do { 1619 // Have we encountered an entrance to a call? It may be 1620 // the case that we have not encountered a matching 1621 // call exit before this point. This means that the path 1622 // terminated within the call itself. 1623 if (Optional<CallEnter> CE = P.getAs<CallEnter>()) { 1624 // Add an edge to the start of the function. 1625 const StackFrameContext *CalleeLC = CE->getCalleeContext(); 1626 const Decl *D = CalleeLC->getDecl(); 1627 addEdgeToPath(PD.getActivePath(), PrevLoc, 1628 PathDiagnosticLocation::createBegin(D, SM), 1629 CalleeLC); 1630 1631 // Did we visit an entire call? 1632 bool VisitedEntireCall = PD.isWithinCall(); 1633 PD.popActivePath(); 1634 1635 PathDiagnosticCallPiece *C; 1636 if (VisitedEntireCall) { 1637 PathDiagnosticPiece *P = PD.getActivePath().front().getPtr(); 1638 C = cast<PathDiagnosticCallPiece>(P); 1639 } else { 1640 const Decl *Caller = CE->getLocationContext()->getDecl(); 1641 C = PathDiagnosticCallPiece::construct(PD.getActivePath(), Caller); 1642 1643 // Since we just transferred the path over to the call piece, 1644 // reset the mapping from active to location context. 1645 assert(PD.getActivePath().size() == 1 && 1646 PD.getActivePath().front() == C); 1647 LCM[&PD.getActivePath()] = 0; 1648 1649 // Record the location context mapping for the path within 1650 // the call. 1651 assert(LCM[&C->path] == 0 || 1652 LCM[&C->path] == CE->getCalleeContext()); 1653 LCM[&C->path] = CE->getCalleeContext(); 1654 1655 // If this is the first item in the active path, record 1656 // the new mapping from active path to location context. 1657 const LocationContext *&NewLC = LCM[&PD.getActivePath()]; 1658 if (!NewLC) 1659 NewLC = N->getLocationContext(); 1660 1661 PDB.LC = NewLC; 1662 } 1663 C->setCallee(*CE, SM); 1664 1665 // Update the previous location in the active path. 1666 PrevLoc = C->getLocation(); 1667 1668 if (!CallStack.empty()) { 1669 assert(CallStack.back().first == C); 1670 CallStack.pop_back(); 1671 } 1672 break; 1673 } 1674 1675 // Query the location context here and the previous location 1676 // as processing CallEnter may change the active path. 1677 PDB.LC = N->getLocationContext(); 1678 1679 // Record the mapping from the active path to the location 1680 // context. 1681 assert(!LCM[&PD.getActivePath()] || 1682 LCM[&PD.getActivePath()] == PDB.LC); 1683 LCM[&PD.getActivePath()] = PDB.LC; 1684 1685 // Have we encountered an exit from a function call? 1686 if (Optional<CallExitEnd> CE = P.getAs<CallExitEnd>()) { 1687 const Stmt *S = CE->getCalleeContext()->getCallSite(); 1688 // Propagate the interesting symbols accordingly. 1689 if (const Expr *Ex = dyn_cast_or_null<Expr>(S)) { 1690 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1691 N->getState().getPtr(), Ex, 1692 N->getLocationContext()); 1693 } 1694 1695 // We are descending into a call (backwards). Construct 1696 // a new call piece to contain the path pieces for that call. 1697 PathDiagnosticCallPiece *C = 1698 PathDiagnosticCallPiece::construct(N, *CE, SM); 1699 1700 // Record the location context for this call piece. 1701 LCM[&C->path] = CE->getCalleeContext(); 1702 1703 // Add the edge to the return site. 1704 addEdgeToPath(PD.getActivePath(), PrevLoc, C->callReturn, PDB.LC); 1705 PD.getActivePath().push_front(C); 1706 PrevLoc.invalidate(); 1707 1708 // Make the contents of the call the active path for now. 1709 PD.pushActivePath(&C->path); 1710 CallStack.push_back(StackDiagPair(C, N)); 1711 break; 1712 } 1713 1714 if (Optional<PostStmt> PS = P.getAs<PostStmt>()) { 1715 // For expressions, make sure we propagate the 1716 // interesting symbols correctly. 1717 if (const Expr *Ex = PS->getStmtAs<Expr>()) 1718 reversePropagateIntererstingSymbols(*PDB.getBugReport(), IE, 1719 N->getState().getPtr(), Ex, 1720 N->getLocationContext()); 1721 1722 // Add an edge. If this is an ObjCForCollectionStmt do 1723 // not add an edge here as it appears in the CFG both 1724 // as a terminator and as a terminator condition. 1725 if (!isa<ObjCForCollectionStmt>(PS->getStmt())) { 1726 PathDiagnosticLocation L = 1727 PathDiagnosticLocation(PS->getStmt(), SM, PDB.LC); 1728 addEdgeToPath(PD.getActivePath(), PrevLoc, L, PDB.LC); 1729 } 1730 break; 1731 } 1732 1733 // Block edges. 1734 if (Optional<BlockEdge> BE = P.getAs<BlockEdge>()) { 1735 // Does this represent entering a call? If so, look at propagating 1736 // interesting symbols across call boundaries. 1737 if (NextNode) { 1738 const LocationContext *CallerCtx = NextNode->getLocationContext(); 1739 const LocationContext *CalleeCtx = PDB.LC; 1740 if (CallerCtx != CalleeCtx) { 1741 reversePropagateInterestingSymbols(*PDB.getBugReport(), IE, 1742 N->getState().getPtr(), 1743 CalleeCtx, CallerCtx); 1744 } 1745 } 1746 1747 // Are we jumping to the head of a loop? Add a special diagnostic. 1748 if (const Stmt *Loop = BE->getSrc()->getLoopTarget()) { 1749 PathDiagnosticLocation L(Loop, SM, PDB.LC); 1750 const Stmt *Body = NULL; 1751 1752 if (const ForStmt *FS = dyn_cast<ForStmt>(Loop)) 1753 Body = FS->getBody(); 1754 else if (const WhileStmt *WS = dyn_cast<WhileStmt>(Loop)) 1755 Body = WS->getBody(); 1756 else if (const ObjCForCollectionStmt *OFS = 1757 dyn_cast<ObjCForCollectionStmt>(Loop)) { 1758 Body = OFS->getBody(); 1759 } else if (const CXXForRangeStmt *FRS = 1760 dyn_cast<CXXForRangeStmt>(Loop)) { 1761 Body = FRS->getBody(); 1762 } 1763 // do-while statements are explicitly excluded here 1764 1765 PathDiagnosticEventPiece *p = 1766 new PathDiagnosticEventPiece(L, "Looping back to the head " 1767 "of the loop"); 1768 p->setPrunable(true); 1769 1770 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), PDB.LC); 1771 PD.getActivePath().push_front(p); 1772 1773 if (const CompoundStmt *CS = dyn_cast_or_null<CompoundStmt>(Body)) { 1774 addEdgeToPath(PD.getActivePath(), PrevLoc, 1775 PathDiagnosticLocation::createEndBrace(CS, SM), 1776 PDB.LC); 1777 } 1778 } 1779 1780 const CFGBlock *BSrc = BE->getSrc(); 1781 ParentMap &PM = PDB.getParentMap(); 1782 1783 if (const Stmt *Term = BSrc->getTerminator()) { 1784 // Are we jumping past the loop body without ever executing the 1785 // loop (because the condition was false)? 1786 if (isLoop(Term)) { 1787 const Stmt *TermCond = getTerminatorCondition(BSrc); 1788 bool IsInLoopBody = 1789 isInLoopBody(PM, getStmtBeforeCond(PM, TermCond, N), Term); 1790 1791 const char *str = 0; 1792 1793 if (isJumpToFalseBranch(&*BE)) { 1794 if (!IsInLoopBody) { 1795 str = StrLoopBodyZero; 1796 } 1797 } 1798 else { 1799 str = StrEnteringLoop; 1800 } 1801 1802 if (str) { 1803 PathDiagnosticLocation L(TermCond ? TermCond : Term, SM, PDB.LC); 1804 PathDiagnosticEventPiece *PE = 1805 new PathDiagnosticEventPiece(L, str); 1806 PE->setPrunable(true); 1807 addEdgeToPath(PD.getActivePath(), PrevLoc, 1808 PE->getLocation(), PDB.LC); 1809 PD.getActivePath().push_front(PE); 1810 } 1811 } 1812 else if (isa<BreakStmt>(Term) || isa<ContinueStmt>(Term) || 1813 isa<GotoStmt>(Term)) { 1814 PathDiagnosticLocation L(Term, SM, PDB.LC); 1815 addEdgeToPath(PD.getActivePath(), PrevLoc, L, PDB.LC); 1816 } 1817 } 1818 break; 1819 } 1820 } while (0); 1821 1822 if (!NextNode) 1823 continue; 1824 1825 // Add pieces from custom visitors. 1826 for (ArrayRef<BugReporterVisitor *>::iterator I = visitors.begin(), 1827 E = visitors.end(); 1828 I != E; ++I) { 1829 if (PathDiagnosticPiece *p = (*I)->VisitNode(N, NextNode, PDB, *report)) { 1830 addEdgeToPath(PD.getActivePath(), PrevLoc, p->getLocation(), PDB.LC); 1831 PD.getActivePath().push_front(p); 1832 updateStackPiecesWithMessage(p, CallStack); 1833 } 1834 } 1835 } 1836 1837 // Add an edge to the start of the function. 1838 // We'll prune it out later, but it helps make diagnostics more uniform. 1839 const StackFrameContext *CalleeLC = PDB.LC->getCurrentStackFrame(); 1840 const Decl *D = CalleeLC->getDecl(); 1841 addEdgeToPath(PD.getActivePath(), PrevLoc, 1842 PathDiagnosticLocation::createBegin(D, SM), 1843 CalleeLC); 1844 1845 return report->isValid(); 1846} 1847 1848static const Stmt *getLocStmt(PathDiagnosticLocation L) { 1849 if (!L.isValid()) 1850 return 0; 1851 return L.asStmt(); 1852} 1853 1854static const Stmt *getStmtParent(const Stmt *S, const ParentMap &PM) { 1855 if (!S) 1856 return 0; 1857 1858 while (true) { 1859 S = PM.getParentIgnoreParens(S); 1860 1861 if (!S) 1862 break; 1863 1864 if (isa<ExprWithCleanups>(S) || 1865 isa<CXXBindTemporaryExpr>(S) || 1866 isa<SubstNonTypeTemplateParmExpr>(S)) 1867 continue; 1868 1869 break; 1870 } 1871 1872 return S; 1873} 1874 1875static bool isConditionForTerminator(const Stmt *S, const Stmt *Cond) { 1876 switch (S->getStmtClass()) { 1877 case Stmt::BinaryOperatorClass: { 1878 const BinaryOperator *BO = cast<BinaryOperator>(S); 1879 if (!BO->isLogicalOp()) 1880 return false; 1881 return BO->getLHS() == Cond || BO->getRHS() == Cond; 1882 } 1883 case Stmt::IfStmtClass: 1884 return cast<IfStmt>(S)->getCond() == Cond; 1885 case Stmt::ForStmtClass: 1886 return cast<ForStmt>(S)->getCond() == Cond; 1887 case Stmt::WhileStmtClass: 1888 return cast<WhileStmt>(S)->getCond() == Cond; 1889 case Stmt::DoStmtClass: 1890 return cast<DoStmt>(S)->getCond() == Cond; 1891 case Stmt::ChooseExprClass: 1892 return cast<ChooseExpr>(S)->getCond() == Cond; 1893 case Stmt::IndirectGotoStmtClass: 1894 return cast<IndirectGotoStmt>(S)->getTarget() == Cond; 1895 case Stmt::SwitchStmtClass: 1896 return cast<SwitchStmt>(S)->getCond() == Cond; 1897 case Stmt::BinaryConditionalOperatorClass: 1898 return cast<BinaryConditionalOperator>(S)->getCond() == Cond; 1899 case Stmt::ConditionalOperatorClass: { 1900 const ConditionalOperator *CO = cast<ConditionalOperator>(S); 1901 return CO->getCond() == Cond || 1902 CO->getLHS() == Cond || 1903 CO->getRHS() == Cond; 1904 } 1905 case Stmt::ObjCForCollectionStmtClass: 1906 return cast<ObjCForCollectionStmt>(S)->getElement() == Cond; 1907 case Stmt::CXXForRangeStmtClass: { 1908 const CXXForRangeStmt *FRS = cast<CXXForRangeStmt>(S); 1909 return FRS->getCond() == Cond || FRS->getRangeInit() == Cond; 1910 } 1911 default: 1912 return false; 1913 } 1914} 1915 1916static bool isIncrementOrInitInForLoop(const Stmt *S, const Stmt *FL) { 1917 if (const ForStmt *FS = dyn_cast<ForStmt>(FL)) 1918 return FS->getInc() == S || FS->getInit() == S; 1919 if (const CXXForRangeStmt *FRS = dyn_cast<CXXForRangeStmt>(FL)) 1920 return FRS->getInc() == S || FRS->getRangeStmt() == S || 1921 FRS->getLoopVarStmt() || FRS->getRangeInit() == S; 1922 return false; 1923} 1924 1925typedef llvm::DenseSet<const PathDiagnosticCallPiece *> 1926 OptimizedCallsSet; 1927 1928/// Adds synthetic edges from top-level statements to their subexpressions. 1929/// 1930/// This avoids a "swoosh" effect, where an edge from a top-level statement A 1931/// points to a sub-expression B.1 that's not at the start of B. In these cases, 1932/// we'd like to see an edge from A to B, then another one from B to B.1. 1933static void addContextEdges(PathPieces &pieces, SourceManager &SM, 1934 const ParentMap &PM, const LocationContext *LCtx) { 1935 PathPieces::iterator Prev = pieces.end(); 1936 for (PathPieces::iterator I = pieces.begin(), E = Prev; I != E; 1937 Prev = I, ++I) { 1938 PathDiagnosticControlFlowPiece *Piece = 1939 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 1940 1941 if (!Piece) 1942 continue; 1943 1944 PathDiagnosticLocation SrcLoc = Piece->getStartLocation(); 1945 SmallVector<PathDiagnosticLocation, 4> SrcContexts; 1946 1947 PathDiagnosticLocation NextSrcContext = SrcLoc; 1948 const Stmt *InnerStmt = 0; 1949 while (NextSrcContext.isValid() && NextSrcContext.asStmt() != InnerStmt) { 1950 SrcContexts.push_back(NextSrcContext); 1951 InnerStmt = NextSrcContext.asStmt(); 1952 NextSrcContext = getEnclosingStmtLocation(InnerStmt, SM, PM, LCtx, 1953 /*allowNested=*/true); 1954 } 1955 1956 // Repeatedly split the edge as necessary. 1957 // This is important for nested logical expressions (||, &&, ?:) where we 1958 // want to show all the levels of context. 1959 while (true) { 1960 const Stmt *Dst = getLocStmt(Piece->getEndLocation()); 1961 1962 // We are looking at an edge. Is the destination within a larger 1963 // expression? 1964 PathDiagnosticLocation DstContext = 1965 getEnclosingStmtLocation(Dst, SM, PM, LCtx, /*allowNested=*/true); 1966 if (!DstContext.isValid() || DstContext.asStmt() == Dst) 1967 break; 1968 1969 // If the source is in the same context, we're already good. 1970 if (std::find(SrcContexts.begin(), SrcContexts.end(), DstContext) != 1971 SrcContexts.end()) 1972 break; 1973 1974 // Update the subexpression node to point to the context edge. 1975 Piece->setStartLocation(DstContext); 1976 1977 // Try to extend the previous edge if it's at the same level as the source 1978 // context. 1979 if (Prev != E) { 1980 PathDiagnosticControlFlowPiece *PrevPiece = 1981 dyn_cast<PathDiagnosticControlFlowPiece>(*Prev); 1982 1983 if (PrevPiece) { 1984 if (const Stmt *PrevSrc = getLocStmt(PrevPiece->getStartLocation())) { 1985 const Stmt *PrevSrcParent = getStmtParent(PrevSrc, PM); 1986 if (PrevSrcParent == getStmtParent(getLocStmt(DstContext), PM)) { 1987 PrevPiece->setEndLocation(DstContext); 1988 break; 1989 } 1990 } 1991 } 1992 } 1993 1994 // Otherwise, split the current edge into a context edge and a 1995 // subexpression edge. Note that the context statement may itself have 1996 // context. 1997 Piece = new PathDiagnosticControlFlowPiece(SrcLoc, DstContext); 1998 I = pieces.insert(I, Piece); 1999 } 2000 } 2001} 2002 2003/// \brief Move edges from a branch condition to a branch target 2004/// when the condition is simple. 2005/// 2006/// This restructures some of the work of addContextEdges. That function 2007/// creates edges this may destroy, but they work together to create a more 2008/// aesthetically set of edges around branches. After the call to 2009/// addContextEdges, we may have (1) an edge to the branch, (2) an edge from 2010/// the branch to the branch condition, and (3) an edge from the branch 2011/// condition to the branch target. We keep (1), but may wish to remove (2) 2012/// and move the source of (3) to the branch if the branch condition is simple. 2013/// 2014static void simplifySimpleBranches(PathPieces &pieces) { 2015 for (PathPieces::iterator I = pieces.begin(), E = pieces.end(); I != E; ++I) { 2016 2017 PathDiagnosticControlFlowPiece *PieceI = 2018 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 2019 2020 if (!PieceI) 2021 continue; 2022 2023 const Stmt *s1Start = getLocStmt(PieceI->getStartLocation()); 2024 const Stmt *s1End = getLocStmt(PieceI->getEndLocation()); 2025 2026 if (!s1Start || !s1End) 2027 continue; 2028 2029 PathPieces::iterator NextI = I; ++NextI; 2030 if (NextI == E) 2031 break; 2032 2033 PathDiagnosticControlFlowPiece *PieceNextI = 0; 2034 2035 while (true) { 2036 if (NextI == E) 2037 break; 2038 2039 PathDiagnosticEventPiece *EV = dyn_cast<PathDiagnosticEventPiece>(*NextI); 2040 if (EV) { 2041 StringRef S = EV->getString(); 2042 if (S == StrEnteringLoop || S == StrLoopBodyZero) { 2043 ++NextI; 2044 continue; 2045 } 2046 break; 2047 } 2048 2049 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 2050 break; 2051 } 2052 2053 if (!PieceNextI) 2054 continue; 2055 2056 const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation()); 2057 const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation()); 2058 2059 if (!s2Start || !s2End || s1End != s2Start) 2060 continue; 2061 2062 // We only perform this transformation for specific branch kinds. 2063 // We don't want to do this for do..while, for example. 2064 if (!(isa<ForStmt>(s1Start) || isa<WhileStmt>(s1Start) || 2065 isa<IfStmt>(s1Start) || isa<ObjCForCollectionStmt>(s1Start) || 2066 isa<CXXForRangeStmt>(s1Start))) 2067 continue; 2068 2069 // Is s1End the branch condition? 2070 if (!isConditionForTerminator(s1Start, s1End)) 2071 continue; 2072 2073 // Perform the hoisting by eliminating (2) and changing the start 2074 // location of (3). 2075 PieceNextI->setStartLocation(PieceI->getStartLocation()); 2076 I = pieces.erase(I); 2077 } 2078} 2079 2080/// Returns the number of bytes in the given (character-based) SourceRange. 2081/// 2082/// If the locations in the range are not on the same line, returns None. 2083/// 2084/// Note that this does not do a precise user-visible character or column count. 2085static Optional<size_t> getLengthOnSingleLine(SourceManager &SM, 2086 SourceRange Range) { 2087 SourceRange ExpansionRange(SM.getExpansionLoc(Range.getBegin()), 2088 SM.getExpansionRange(Range.getEnd()).second); 2089 2090 FileID FID = SM.getFileID(ExpansionRange.getBegin()); 2091 if (FID != SM.getFileID(ExpansionRange.getEnd())) 2092 return None; 2093 2094 bool Invalid; 2095 const llvm::MemoryBuffer *Buffer = SM.getBuffer(FID, &Invalid); 2096 if (Invalid) 2097 return None; 2098 2099 unsigned BeginOffset = SM.getFileOffset(ExpansionRange.getBegin()); 2100 unsigned EndOffset = SM.getFileOffset(ExpansionRange.getEnd()); 2101 StringRef Snippet = Buffer->getBuffer().slice(BeginOffset, EndOffset); 2102 2103 // We're searching the raw bytes of the buffer here, which might include 2104 // escaped newlines and such. That's okay; we're trying to decide whether the 2105 // SourceRange is covering a large or small amount of space in the user's 2106 // editor. 2107 if (Snippet.find_first_of("\r\n") != StringRef::npos) 2108 return None; 2109 2110 // This isn't Unicode-aware, but it doesn't need to be. 2111 return Snippet.size(); 2112} 2113 2114/// \sa getLengthOnSingleLine(SourceManager, SourceRange) 2115static Optional<size_t> getLengthOnSingleLine(SourceManager &SM, 2116 const Stmt *S) { 2117 return getLengthOnSingleLine(SM, S->getSourceRange()); 2118} 2119 2120/// Eliminate two-edge cycles created by addContextEdges(). 2121/// 2122/// Once all the context edges are in place, there are plenty of cases where 2123/// there's a single edge from a top-level statement to a subexpression, 2124/// followed by a single path note, and then a reverse edge to get back out to 2125/// the top level. If the statement is simple enough, the subexpression edges 2126/// just add noise and make it harder to understand what's going on. 2127/// 2128/// This function only removes edges in pairs, because removing only one edge 2129/// might leave other edges dangling. 2130/// 2131/// This will not remove edges in more complicated situations: 2132/// - if there is more than one "hop" leading to or from a subexpression. 2133/// - if there is an inlined call between the edges instead of a single event. 2134/// - if the whole statement is large enough that having subexpression arrows 2135/// might be helpful. 2136static void removeContextCycles(PathPieces &Path, SourceManager &SM, 2137 ParentMap &PM) { 2138 for (PathPieces::iterator I = Path.begin(), E = Path.end(); I != E; ) { 2139 // Pattern match the current piece and its successor. 2140 PathDiagnosticControlFlowPiece *PieceI = 2141 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 2142 2143 if (!PieceI) { 2144 ++I; 2145 continue; 2146 } 2147 2148 const Stmt *s1Start = getLocStmt(PieceI->getStartLocation()); 2149 const Stmt *s1End = getLocStmt(PieceI->getEndLocation()); 2150 2151 PathPieces::iterator NextI = I; ++NextI; 2152 if (NextI == E) 2153 break; 2154 2155 PathDiagnosticControlFlowPiece *PieceNextI = 2156 dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 2157 2158 if (!PieceNextI) { 2159 if (isa<PathDiagnosticEventPiece>(*NextI)) { 2160 ++NextI; 2161 if (NextI == E) 2162 break; 2163 PieceNextI = dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 2164 } 2165 2166 if (!PieceNextI) { 2167 ++I; 2168 continue; 2169 } 2170 } 2171 2172 const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation()); 2173 const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation()); 2174 2175 if (s1Start && s2Start && s1Start == s2End && s2Start == s1End) { 2176 const size_t MAX_SHORT_LINE_LENGTH = 80; 2177 Optional<size_t> s1Length = getLengthOnSingleLine(SM, s1Start); 2178 if (s1Length && *s1Length <= MAX_SHORT_LINE_LENGTH) { 2179 Optional<size_t> s2Length = getLengthOnSingleLine(SM, s2Start); 2180 if (s2Length && *s2Length <= MAX_SHORT_LINE_LENGTH) { 2181 Path.erase(I); 2182 I = Path.erase(NextI); 2183 continue; 2184 } 2185 } 2186 } 2187 2188 ++I; 2189 } 2190} 2191 2192/// \brief Return true if X is contained by Y. 2193static bool lexicalContains(ParentMap &PM, 2194 const Stmt *X, 2195 const Stmt *Y) { 2196 while (X) { 2197 if (X == Y) 2198 return true; 2199 X = PM.getParent(X); 2200 } 2201 return false; 2202} 2203 2204// Remove short edges on the same line less than 3 columns in difference. 2205static void removePunyEdges(PathPieces &path, 2206 SourceManager &SM, 2207 ParentMap &PM) { 2208 2209 bool erased = false; 2210 2211 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; 2212 erased ? I : ++I) { 2213 2214 erased = false; 2215 2216 PathDiagnosticControlFlowPiece *PieceI = 2217 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 2218 2219 if (!PieceI) 2220 continue; 2221 2222 const Stmt *start = getLocStmt(PieceI->getStartLocation()); 2223 const Stmt *end = getLocStmt(PieceI->getEndLocation()); 2224 2225 if (!start || !end) 2226 continue; 2227 2228 const Stmt *endParent = PM.getParent(end); 2229 if (!endParent) 2230 continue; 2231 2232 if (isConditionForTerminator(end, endParent)) 2233 continue; 2234 2235 SourceLocation FirstLoc = start->getLocStart(); 2236 SourceLocation SecondLoc = end->getLocStart(); 2237 2238 if (!SM.isFromSameFile(FirstLoc, SecondLoc)) 2239 continue; 2240 if (SM.isBeforeInTranslationUnit(SecondLoc, FirstLoc)) 2241 std::swap(SecondLoc, FirstLoc); 2242 2243 SourceRange EdgeRange(FirstLoc, SecondLoc); 2244 Optional<size_t> ByteWidth = getLengthOnSingleLine(SM, EdgeRange); 2245 2246 // If the statements are on different lines, continue. 2247 if (!ByteWidth) 2248 continue; 2249 2250 const size_t MAX_PUNY_EDGE_LENGTH = 2; 2251 if (*ByteWidth <= MAX_PUNY_EDGE_LENGTH) { 2252 // FIXME: There are enough /bytes/ between the endpoints of the edge, but 2253 // there might not be enough /columns/. A proper user-visible column count 2254 // is probably too expensive, though. 2255 I = path.erase(I); 2256 erased = true; 2257 continue; 2258 } 2259 } 2260} 2261 2262static void removeIdenticalEvents(PathPieces &path) { 2263 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ++I) { 2264 PathDiagnosticEventPiece *PieceI = 2265 dyn_cast<PathDiagnosticEventPiece>(*I); 2266 2267 if (!PieceI) 2268 continue; 2269 2270 PathPieces::iterator NextI = I; ++NextI; 2271 if (NextI == E) 2272 return; 2273 2274 PathDiagnosticEventPiece *PieceNextI = 2275 dyn_cast<PathDiagnosticEventPiece>(*NextI); 2276 2277 if (!PieceNextI) 2278 continue; 2279 2280 // Erase the second piece if it has the same exact message text. 2281 if (PieceI->getString() == PieceNextI->getString()) { 2282 path.erase(NextI); 2283 } 2284 } 2285} 2286 2287static bool optimizeEdges(PathPieces &path, SourceManager &SM, 2288 OptimizedCallsSet &OCS, 2289 LocationContextMap &LCM) { 2290 bool hasChanges = false; 2291 const LocationContext *LC = LCM[&path]; 2292 assert(LC); 2293 ParentMap &PM = LC->getParentMap(); 2294 2295 for (PathPieces::iterator I = path.begin(), E = path.end(); I != E; ) { 2296 // Optimize subpaths. 2297 if (PathDiagnosticCallPiece *CallI = dyn_cast<PathDiagnosticCallPiece>(*I)){ 2298 // Record the fact that a call has been optimized so we only do the 2299 // effort once. 2300 if (!OCS.count(CallI)) { 2301 while (optimizeEdges(CallI->path, SM, OCS, LCM)) {} 2302 OCS.insert(CallI); 2303 } 2304 ++I; 2305 continue; 2306 } 2307 2308 // Pattern match the current piece and its successor. 2309 PathDiagnosticControlFlowPiece *PieceI = 2310 dyn_cast<PathDiagnosticControlFlowPiece>(*I); 2311 2312 if (!PieceI) { 2313 ++I; 2314 continue; 2315 } 2316 2317 const Stmt *s1Start = getLocStmt(PieceI->getStartLocation()); 2318 const Stmt *s1End = getLocStmt(PieceI->getEndLocation()); 2319 const Stmt *level1 = getStmtParent(s1Start, PM); 2320 const Stmt *level2 = getStmtParent(s1End, PM); 2321 2322 PathPieces::iterator NextI = I; ++NextI; 2323 if (NextI == E) 2324 break; 2325 2326 PathDiagnosticControlFlowPiece *PieceNextI = 2327 dyn_cast<PathDiagnosticControlFlowPiece>(*NextI); 2328 2329 if (!PieceNextI) { 2330 ++I; 2331 continue; 2332 } 2333 2334 const Stmt *s2Start = getLocStmt(PieceNextI->getStartLocation()); 2335 const Stmt *s2End = getLocStmt(PieceNextI->getEndLocation()); 2336 const Stmt *level3 = getStmtParent(s2Start, PM); 2337 const Stmt *level4 = getStmtParent(s2End, PM); 2338 2339 // Rule I. 2340 // 2341 // If we have two consecutive control edges whose end/begin locations 2342 // are at the same level (e.g. statements or top-level expressions within 2343 // a compound statement, or siblings share a single ancestor expression), 2344 // then merge them if they have no interesting intermediate event. 2345 // 2346 // For example: 2347 // 2348 // (1.1 -> 1.2) -> (1.2 -> 1.3) becomes (1.1 -> 1.3) because the common 2349 // parent is '1'. Here 'x.y.z' represents the hierarchy of statements. 2350 // 2351 // NOTE: this will be limited later in cases where we add barriers 2352 // to prevent this optimization. 2353 // 2354 if (level1 && level1 == level2 && level1 == level3 && level1 == level4) { 2355 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2356 path.erase(NextI); 2357 hasChanges = true; 2358 continue; 2359 } 2360 2361 // Rule II. 2362 // 2363 // Eliminate edges between subexpressions and parent expressions 2364 // when the subexpression is consumed. 2365 // 2366 // NOTE: this will be limited later in cases where we add barriers 2367 // to prevent this optimization. 2368 // 2369 if (s1End && s1End == s2Start && level2) { 2370 bool removeEdge = false; 2371 // Remove edges into the increment or initialization of a 2372 // loop that have no interleaving event. This means that 2373 // they aren't interesting. 2374 if (isIncrementOrInitInForLoop(s1End, level2)) 2375 removeEdge = true; 2376 // Next only consider edges that are not anchored on 2377 // the condition of a terminator. This are intermediate edges 2378 // that we might want to trim. 2379 else if (!isConditionForTerminator(level2, s1End)) { 2380 // Trim edges on expressions that are consumed by 2381 // the parent expression. 2382 if (isa<Expr>(s1End) && PM.isConsumedExpr(cast<Expr>(s1End))) { 2383 removeEdge = true; 2384 } 2385 // Trim edges where a lexical containment doesn't exist. 2386 // For example: 2387 // 2388 // X -> Y -> Z 2389 // 2390 // If 'Z' lexically contains Y (it is an ancestor) and 2391 // 'X' does not lexically contain Y (it is a descendant OR 2392 // it has no lexical relationship at all) then trim. 2393 // 2394 // This can eliminate edges where we dive into a subexpression 2395 // and then pop back out, etc. 2396 else if (s1Start && s2End && 2397 lexicalContains(PM, s2Start, s2End) && 2398 !lexicalContains(PM, s1End, s1Start)) { 2399 removeEdge = true; 2400 } 2401 // Trim edges from a subexpression back to the top level if the 2402 // subexpression is on a different line. 2403 // 2404 // A.1 -> A -> B 2405 // becomes 2406 // A.1 -> B 2407 // 2408 // These edges just look ugly and don't usually add anything. 2409 else if (s1Start && s2End && 2410 lexicalContains(PM, s1Start, s1End)) { 2411 SourceRange EdgeRange(PieceI->getEndLocation().asLocation(), 2412 PieceI->getStartLocation().asLocation()); 2413 if (!getLengthOnSingleLine(SM, EdgeRange).hasValue()) 2414 removeEdge = true; 2415 } 2416 } 2417 2418 if (removeEdge) { 2419 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2420 path.erase(NextI); 2421 hasChanges = true; 2422 continue; 2423 } 2424 } 2425 2426 // Optimize edges for ObjC fast-enumeration loops. 2427 // 2428 // (X -> collection) -> (collection -> element) 2429 // 2430 // becomes: 2431 // 2432 // (X -> element) 2433 if (s1End == s2Start) { 2434 const ObjCForCollectionStmt *FS = 2435 dyn_cast_or_null<ObjCForCollectionStmt>(level3); 2436 if (FS && FS->getCollection()->IgnoreParens() == s2Start && 2437 s2End == FS->getElement()) { 2438 PieceI->setEndLocation(PieceNextI->getEndLocation()); 2439 path.erase(NextI); 2440 hasChanges = true; 2441 continue; 2442 } 2443 } 2444 2445 // No changes at this index? Move to the next one. 2446 ++I; 2447 } 2448 2449 if (!hasChanges) { 2450 // Adjust edges into subexpressions to make them more uniform 2451 // and aesthetically pleasing. 2452 addContextEdges(path, SM, PM, LC); 2453 // Remove "cyclical" edges that include one or more context edges. 2454 removeContextCycles(path, SM, PM); 2455 // Hoist edges originating from branch conditions to branches 2456 // for simple branches. 2457 simplifySimpleBranches(path); 2458 // Remove any puny edges left over after primary optimization pass. 2459 removePunyEdges(path, SM, PM); 2460 // Remove identical events. 2461 removeIdenticalEvents(path); 2462 } 2463 2464 return hasChanges; 2465} 2466 2467/// Drop the very first edge in a path, which should be a function entry edge. 2468/// 2469/// If the first edge is not a function entry edge (say, because the first 2470/// statement had an invalid source location), this function does nothing. 2471// FIXME: We should just generate invalid edges anyway and have the optimizer 2472// deal with them. 2473static void dropFunctionEntryEdge(PathPieces &Path, 2474 LocationContextMap &LCM, 2475 SourceManager &SM) { 2476 const PathDiagnosticControlFlowPiece *FirstEdge = 2477 dyn_cast<PathDiagnosticControlFlowPiece>(Path.front()); 2478 if (!FirstEdge) 2479 return; 2480 2481 const Decl *D = LCM[&Path]->getDecl(); 2482 PathDiagnosticLocation EntryLoc = PathDiagnosticLocation::createBegin(D, SM); 2483 if (FirstEdge->getStartLocation() != EntryLoc) 2484 return; 2485 2486 Path.pop_front(); 2487} 2488 2489 2490//===----------------------------------------------------------------------===// 2491// Methods for BugType and subclasses. 2492//===----------------------------------------------------------------------===// 2493BugType::~BugType() { } 2494 2495void BugType::FlushReports(BugReporter &BR) {} 2496 2497void BuiltinBug::anchor() {} 2498 2499//===----------------------------------------------------------------------===// 2500// Methods for BugReport and subclasses. 2501//===----------------------------------------------------------------------===// 2502 2503void BugReport::NodeResolver::anchor() {} 2504 2505void BugReport::addVisitor(BugReporterVisitor* visitor) { 2506 if (!visitor) 2507 return; 2508 2509 llvm::FoldingSetNodeID ID; 2510 visitor->Profile(ID); 2511 void *InsertPos; 2512 2513 if (CallbacksSet.FindNodeOrInsertPos(ID, InsertPos)) { 2514 delete visitor; 2515 return; 2516 } 2517 2518 CallbacksSet.InsertNode(visitor, InsertPos); 2519 Callbacks.push_back(visitor); 2520 ++ConfigurationChangeToken; 2521} 2522 2523BugReport::~BugReport() { 2524 for (visitor_iterator I = visitor_begin(), E = visitor_end(); I != E; ++I) { 2525 delete *I; 2526 } 2527 while (!interestingSymbols.empty()) { 2528 popInterestingSymbolsAndRegions(); 2529 } 2530} 2531 2532const Decl *BugReport::getDeclWithIssue() const { 2533 if (DeclWithIssue) 2534 return DeclWithIssue; 2535 2536 const ExplodedNode *N = getErrorNode(); 2537 if (!N) 2538 return 0; 2539 2540 const LocationContext *LC = N->getLocationContext(); 2541 return LC->getCurrentStackFrame()->getDecl(); 2542} 2543 2544void BugReport::Profile(llvm::FoldingSetNodeID& hash) const { 2545 hash.AddPointer(&BT); 2546 hash.AddString(Description); 2547 PathDiagnosticLocation UL = getUniqueingLocation(); 2548 if (UL.isValid()) { 2549 UL.Profile(hash); 2550 } else if (Location.isValid()) { 2551 Location.Profile(hash); 2552 } else { 2553 assert(ErrorNode); 2554 hash.AddPointer(GetCurrentOrPreviousStmt(ErrorNode)); 2555 } 2556 2557 for (SmallVectorImpl<SourceRange>::const_iterator I = 2558 Ranges.begin(), E = Ranges.end(); I != E; ++I) { 2559 const SourceRange range = *I; 2560 if (!range.isValid()) 2561 continue; 2562 hash.AddInteger(range.getBegin().getRawEncoding()); 2563 hash.AddInteger(range.getEnd().getRawEncoding()); 2564 } 2565} 2566 2567void BugReport::markInteresting(SymbolRef sym) { 2568 if (!sym) 2569 return; 2570 2571 // If the symbol wasn't already in our set, note a configuration change. 2572 if (getInterestingSymbols().insert(sym).second) 2573 ++ConfigurationChangeToken; 2574 2575 if (const SymbolMetadata *meta = dyn_cast<SymbolMetadata>(sym)) 2576 getInterestingRegions().insert(meta->getRegion()); 2577} 2578 2579void BugReport::markInteresting(const MemRegion *R) { 2580 if (!R) 2581 return; 2582 2583 // If the base region wasn't already in our set, note a configuration change. 2584 R = R->getBaseRegion(); 2585 if (getInterestingRegions().insert(R).second) 2586 ++ConfigurationChangeToken; 2587 2588 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2589 getInterestingSymbols().insert(SR->getSymbol()); 2590} 2591 2592void BugReport::markInteresting(SVal V) { 2593 markInteresting(V.getAsRegion()); 2594 markInteresting(V.getAsSymbol()); 2595} 2596 2597void BugReport::markInteresting(const LocationContext *LC) { 2598 if (!LC) 2599 return; 2600 InterestingLocationContexts.insert(LC); 2601} 2602 2603bool BugReport::isInteresting(SVal V) { 2604 return isInteresting(V.getAsRegion()) || isInteresting(V.getAsSymbol()); 2605} 2606 2607bool BugReport::isInteresting(SymbolRef sym) { 2608 if (!sym) 2609 return false; 2610 // We don't currently consider metadata symbols to be interesting 2611 // even if we know their region is interesting. Is that correct behavior? 2612 return getInterestingSymbols().count(sym); 2613} 2614 2615bool BugReport::isInteresting(const MemRegion *R) { 2616 if (!R) 2617 return false; 2618 R = R->getBaseRegion(); 2619 bool b = getInterestingRegions().count(R); 2620 if (b) 2621 return true; 2622 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) 2623 return getInterestingSymbols().count(SR->getSymbol()); 2624 return false; 2625} 2626 2627bool BugReport::isInteresting(const LocationContext *LC) { 2628 if (!LC) 2629 return false; 2630 return InterestingLocationContexts.count(LC); 2631} 2632 2633void BugReport::lazyInitializeInterestingSets() { 2634 if (interestingSymbols.empty()) { 2635 interestingSymbols.push_back(new Symbols()); 2636 interestingRegions.push_back(new Regions()); 2637 } 2638} 2639 2640BugReport::Symbols &BugReport::getInterestingSymbols() { 2641 lazyInitializeInterestingSets(); 2642 return *interestingSymbols.back(); 2643} 2644 2645BugReport::Regions &BugReport::getInterestingRegions() { 2646 lazyInitializeInterestingSets(); 2647 return *interestingRegions.back(); 2648} 2649 2650void BugReport::pushInterestingSymbolsAndRegions() { 2651 interestingSymbols.push_back(new Symbols(getInterestingSymbols())); 2652 interestingRegions.push_back(new Regions(getInterestingRegions())); 2653} 2654 2655void BugReport::popInterestingSymbolsAndRegions() { 2656 delete interestingSymbols.back(); 2657 interestingSymbols.pop_back(); 2658 delete interestingRegions.back(); 2659 interestingRegions.pop_back(); 2660} 2661 2662const Stmt *BugReport::getStmt() const { 2663 if (!ErrorNode) 2664 return 0; 2665 2666 ProgramPoint ProgP = ErrorNode->getLocation(); 2667 const Stmt *S = NULL; 2668 2669 if (Optional<BlockEntrance> BE = ProgP.getAs<BlockEntrance>()) { 2670 CFGBlock &Exit = ProgP.getLocationContext()->getCFG()->getExit(); 2671 if (BE->getBlock() == &Exit) 2672 S = GetPreviousStmt(ErrorNode); 2673 } 2674 if (!S) 2675 S = PathDiagnosticLocation::getStmt(ErrorNode); 2676 2677 return S; 2678} 2679 2680std::pair<BugReport::ranges_iterator, BugReport::ranges_iterator> 2681BugReport::getRanges() { 2682 // If no custom ranges, add the range of the statement corresponding to 2683 // the error node. 2684 if (Ranges.empty()) { 2685 if (const Expr *E = dyn_cast_or_null<Expr>(getStmt())) 2686 addRange(E->getSourceRange()); 2687 else 2688 return std::make_pair(ranges_iterator(), ranges_iterator()); 2689 } 2690 2691 // User-specified absence of range info. 2692 if (Ranges.size() == 1 && !Ranges.begin()->isValid()) 2693 return std::make_pair(ranges_iterator(), ranges_iterator()); 2694 2695 return std::make_pair(Ranges.begin(), Ranges.end()); 2696} 2697 2698PathDiagnosticLocation BugReport::getLocation(const SourceManager &SM) const { 2699 if (ErrorNode) { 2700 assert(!Location.isValid() && 2701 "Either Location or ErrorNode should be specified but not both."); 2702 return PathDiagnosticLocation::createEndOfPath(ErrorNode, SM); 2703 } else { 2704 assert(Location.isValid()); 2705 return Location; 2706 } 2707 2708 return PathDiagnosticLocation(); 2709} 2710 2711//===----------------------------------------------------------------------===// 2712// Methods for BugReporter and subclasses. 2713//===----------------------------------------------------------------------===// 2714 2715BugReportEquivClass::~BugReportEquivClass() { } 2716GRBugReporter::~GRBugReporter() { } 2717BugReporterData::~BugReporterData() {} 2718 2719ExplodedGraph &GRBugReporter::getGraph() { return Eng.getGraph(); } 2720 2721ProgramStateManager& 2722GRBugReporter::getStateManager() { return Eng.getStateManager(); } 2723 2724BugReporter::~BugReporter() { 2725 FlushReports(); 2726 2727 // Free the bug reports we are tracking. 2728 typedef std::vector<BugReportEquivClass *> ContTy; 2729 for (ContTy::iterator I = EQClassesVector.begin(), E = EQClassesVector.end(); 2730 I != E; ++I) { 2731 delete *I; 2732 } 2733} 2734 2735void BugReporter::FlushReports() { 2736 if (BugTypes.isEmpty()) 2737 return; 2738 2739 // First flush the warnings for each BugType. This may end up creating new 2740 // warnings and new BugTypes. 2741 // FIXME: Only NSErrorChecker needs BugType's FlushReports. 2742 // Turn NSErrorChecker into a proper checker and remove this. 2743 SmallVector<const BugType*, 16> bugTypes; 2744 for (BugTypesTy::iterator I=BugTypes.begin(), E=BugTypes.end(); I!=E; ++I) 2745 bugTypes.push_back(*I); 2746 for (SmallVector<const BugType*, 16>::iterator 2747 I = bugTypes.begin(), E = bugTypes.end(); I != E; ++I) 2748 const_cast<BugType*>(*I)->FlushReports(*this); 2749 2750 // We need to flush reports in deterministic order to ensure the order 2751 // of the reports is consistent between runs. 2752 typedef std::vector<BugReportEquivClass *> ContVecTy; 2753 for (ContVecTy::iterator EI=EQClassesVector.begin(), EE=EQClassesVector.end(); 2754 EI != EE; ++EI){ 2755 BugReportEquivClass& EQ = **EI; 2756 FlushReport(EQ); 2757 } 2758 2759 // BugReporter owns and deletes only BugTypes created implicitly through 2760 // EmitBasicReport. 2761 // FIXME: There are leaks from checkers that assume that the BugTypes they 2762 // create will be destroyed by the BugReporter. 2763 for (llvm::StringMap<BugType*>::iterator 2764 I = StrBugTypes.begin(), E = StrBugTypes.end(); I != E; ++I) 2765 delete I->second; 2766 2767 // Remove all references to the BugType objects. 2768 BugTypes = F.getEmptySet(); 2769} 2770 2771//===----------------------------------------------------------------------===// 2772// PathDiagnostics generation. 2773//===----------------------------------------------------------------------===// 2774 2775namespace { 2776/// A wrapper around a report graph, which contains only a single path, and its 2777/// node maps. 2778class ReportGraph { 2779public: 2780 InterExplodedGraphMap BackMap; 2781 OwningPtr<ExplodedGraph> Graph; 2782 const ExplodedNode *ErrorNode; 2783 size_t Index; 2784}; 2785 2786/// A wrapper around a trimmed graph and its node maps. 2787class TrimmedGraph { 2788 InterExplodedGraphMap InverseMap; 2789 2790 typedef llvm::DenseMap<const ExplodedNode *, unsigned> PriorityMapTy; 2791 PriorityMapTy PriorityMap; 2792 2793 typedef std::pair<const ExplodedNode *, size_t> NodeIndexPair; 2794 SmallVector<NodeIndexPair, 32> ReportNodes; 2795 2796 OwningPtr<ExplodedGraph> G; 2797 2798 /// A helper class for sorting ExplodedNodes by priority. 2799 template <bool Descending> 2800 class PriorityCompare { 2801 const PriorityMapTy &PriorityMap; 2802 2803 public: 2804 PriorityCompare(const PriorityMapTy &M) : PriorityMap(M) {} 2805 2806 bool operator()(const ExplodedNode *LHS, const ExplodedNode *RHS) const { 2807 PriorityMapTy::const_iterator LI = PriorityMap.find(LHS); 2808 PriorityMapTy::const_iterator RI = PriorityMap.find(RHS); 2809 PriorityMapTy::const_iterator E = PriorityMap.end(); 2810 2811 if (LI == E) 2812 return Descending; 2813 if (RI == E) 2814 return !Descending; 2815 2816 return Descending ? LI->second > RI->second 2817 : LI->second < RI->second; 2818 } 2819 2820 bool operator()(const NodeIndexPair &LHS, const NodeIndexPair &RHS) const { 2821 return (*this)(LHS.first, RHS.first); 2822 } 2823 }; 2824 2825public: 2826 TrimmedGraph(const ExplodedGraph *OriginalGraph, 2827 ArrayRef<const ExplodedNode *> Nodes); 2828 2829 bool popNextReportGraph(ReportGraph &GraphWrapper); 2830}; 2831} 2832 2833TrimmedGraph::TrimmedGraph(const ExplodedGraph *OriginalGraph, 2834 ArrayRef<const ExplodedNode *> Nodes) { 2835 // The trimmed graph is created in the body of the constructor to ensure 2836 // that the DenseMaps have been initialized already. 2837 InterExplodedGraphMap ForwardMap; 2838 G.reset(OriginalGraph->trim(Nodes, &ForwardMap, &InverseMap)); 2839 2840 // Find the (first) error node in the trimmed graph. We just need to consult 2841 // the node map which maps from nodes in the original graph to nodes 2842 // in the new graph. 2843 llvm::SmallPtrSet<const ExplodedNode *, 32> RemainingNodes; 2844 2845 for (unsigned i = 0, count = Nodes.size(); i < count; ++i) { 2846 if (const ExplodedNode *NewNode = ForwardMap.lookup(Nodes[i])) { 2847 ReportNodes.push_back(std::make_pair(NewNode, i)); 2848 RemainingNodes.insert(NewNode); 2849 } 2850 } 2851 2852 assert(!RemainingNodes.empty() && "No error node found in the trimmed graph"); 2853 2854 // Perform a forward BFS to find all the shortest paths. 2855 std::queue<const ExplodedNode *> WS; 2856 2857 assert(G->num_roots() == 1); 2858 WS.push(*G->roots_begin()); 2859 unsigned Priority = 0; 2860 2861 while (!WS.empty()) { 2862 const ExplodedNode *Node = WS.front(); 2863 WS.pop(); 2864 2865 PriorityMapTy::iterator PriorityEntry; 2866 bool IsNew; 2867 llvm::tie(PriorityEntry, IsNew) = 2868 PriorityMap.insert(std::make_pair(Node, Priority)); 2869 ++Priority; 2870 2871 if (!IsNew) { 2872 assert(PriorityEntry->second <= Priority); 2873 continue; 2874 } 2875 2876 if (RemainingNodes.erase(Node)) 2877 if (RemainingNodes.empty()) 2878 break; 2879 2880 for (ExplodedNode::const_pred_iterator I = Node->succ_begin(), 2881 E = Node->succ_end(); 2882 I != E; ++I) 2883 WS.push(*I); 2884 } 2885 2886 // Sort the error paths from longest to shortest. 2887 std::sort(ReportNodes.begin(), ReportNodes.end(), 2888 PriorityCompare<true>(PriorityMap)); 2889} 2890 2891bool TrimmedGraph::popNextReportGraph(ReportGraph &GraphWrapper) { 2892 if (ReportNodes.empty()) 2893 return false; 2894 2895 const ExplodedNode *OrigN; 2896 llvm::tie(OrigN, GraphWrapper.Index) = ReportNodes.pop_back_val(); 2897 assert(PriorityMap.find(OrigN) != PriorityMap.end() && 2898 "error node not accessible from root"); 2899 2900 // Create a new graph with a single path. This is the graph 2901 // that will be returned to the caller. 2902 ExplodedGraph *GNew = new ExplodedGraph(); 2903 GraphWrapper.Graph.reset(GNew); 2904 GraphWrapper.BackMap.clear(); 2905 2906 // Now walk from the error node up the BFS path, always taking the 2907 // predeccessor with the lowest number. 2908 ExplodedNode *Succ = 0; 2909 while (true) { 2910 // Create the equivalent node in the new graph with the same state 2911 // and location. 2912 ExplodedNode *NewN = GNew->getNode(OrigN->getLocation(), OrigN->getState(), 2913 OrigN->isSink()); 2914 2915 // Store the mapping to the original node. 2916 InterExplodedGraphMap::const_iterator IMitr = InverseMap.find(OrigN); 2917 assert(IMitr != InverseMap.end() && "No mapping to original node."); 2918 GraphWrapper.BackMap[NewN] = IMitr->second; 2919 2920 // Link up the new node with the previous node. 2921 if (Succ) 2922 Succ->addPredecessor(NewN, *GNew); 2923 else 2924 GraphWrapper.ErrorNode = NewN; 2925 2926 Succ = NewN; 2927 2928 // Are we at the final node? 2929 if (OrigN->pred_empty()) { 2930 GNew->addRoot(NewN); 2931 break; 2932 } 2933 2934 // Find the next predeccessor node. We choose the node that is marked 2935 // with the lowest BFS number. 2936 OrigN = *std::min_element(OrigN->pred_begin(), OrigN->pred_end(), 2937 PriorityCompare<false>(PriorityMap)); 2938 } 2939 2940 return true; 2941} 2942 2943 2944/// CompactPathDiagnostic - This function postprocesses a PathDiagnostic object 2945/// and collapses PathDiagosticPieces that are expanded by macros. 2946static void CompactPathDiagnostic(PathPieces &path, const SourceManager& SM) { 2947 typedef std::vector<std::pair<IntrusiveRefCntPtr<PathDiagnosticMacroPiece>, 2948 SourceLocation> > MacroStackTy; 2949 2950 typedef std::vector<IntrusiveRefCntPtr<PathDiagnosticPiece> > 2951 PiecesTy; 2952 2953 MacroStackTy MacroStack; 2954 PiecesTy Pieces; 2955 2956 for (PathPieces::const_iterator I = path.begin(), E = path.end(); 2957 I!=E; ++I) { 2958 2959 PathDiagnosticPiece *piece = I->getPtr(); 2960 2961 // Recursively compact calls. 2962 if (PathDiagnosticCallPiece *call=dyn_cast<PathDiagnosticCallPiece>(piece)){ 2963 CompactPathDiagnostic(call->path, SM); 2964 } 2965 2966 // Get the location of the PathDiagnosticPiece. 2967 const FullSourceLoc Loc = piece->getLocation().asLocation(); 2968 2969 // Determine the instantiation location, which is the location we group 2970 // related PathDiagnosticPieces. 2971 SourceLocation InstantiationLoc = Loc.isMacroID() ? 2972 SM.getExpansionLoc(Loc) : 2973 SourceLocation(); 2974 2975 if (Loc.isFileID()) { 2976 MacroStack.clear(); 2977 Pieces.push_back(piece); 2978 continue; 2979 } 2980 2981 assert(Loc.isMacroID()); 2982 2983 // Is the PathDiagnosticPiece within the same macro group? 2984 if (!MacroStack.empty() && InstantiationLoc == MacroStack.back().second) { 2985 MacroStack.back().first->subPieces.push_back(piece); 2986 continue; 2987 } 2988 2989 // We aren't in the same group. Are we descending into a new macro 2990 // or are part of an old one? 2991 IntrusiveRefCntPtr<PathDiagnosticMacroPiece> MacroGroup; 2992 2993 SourceLocation ParentInstantiationLoc = InstantiationLoc.isMacroID() ? 2994 SM.getExpansionLoc(Loc) : 2995 SourceLocation(); 2996 2997 // Walk the entire macro stack. 2998 while (!MacroStack.empty()) { 2999 if (InstantiationLoc == MacroStack.back().second) { 3000 MacroGroup = MacroStack.back().first; 3001 break; 3002 } 3003 3004 if (ParentInstantiationLoc == MacroStack.back().second) { 3005 MacroGroup = MacroStack.back().first; 3006 break; 3007 } 3008 3009 MacroStack.pop_back(); 3010 } 3011 3012 if (!MacroGroup || ParentInstantiationLoc == MacroStack.back().second) { 3013 // Create a new macro group and add it to the stack. 3014 PathDiagnosticMacroPiece *NewGroup = 3015 new PathDiagnosticMacroPiece( 3016 PathDiagnosticLocation::createSingleLocation(piece->getLocation())); 3017 3018 if (MacroGroup) 3019 MacroGroup->subPieces.push_back(NewGroup); 3020 else { 3021 assert(InstantiationLoc.isFileID()); 3022 Pieces.push_back(NewGroup); 3023 } 3024 3025 MacroGroup = NewGroup; 3026 MacroStack.push_back(std::make_pair(MacroGroup, InstantiationLoc)); 3027 } 3028 3029 // Finally, add the PathDiagnosticPiece to the group. 3030 MacroGroup->subPieces.push_back(piece); 3031 } 3032 3033 // Now take the pieces and construct a new PathDiagnostic. 3034 path.clear(); 3035 3036 for (PiecesTy::iterator I=Pieces.begin(), E=Pieces.end(); I!=E; ++I) 3037 path.push_back(*I); 3038} 3039 3040bool GRBugReporter::generatePathDiagnostic(PathDiagnostic& PD, 3041 PathDiagnosticConsumer &PC, 3042 ArrayRef<BugReport *> &bugReports) { 3043 assert(!bugReports.empty()); 3044 3045 bool HasValid = false; 3046 bool HasInvalid = false; 3047 SmallVector<const ExplodedNode *, 32> errorNodes; 3048 for (ArrayRef<BugReport*>::iterator I = bugReports.begin(), 3049 E = bugReports.end(); I != E; ++I) { 3050 if ((*I)->isValid()) { 3051 HasValid = true; 3052 errorNodes.push_back((*I)->getErrorNode()); 3053 } else { 3054 // Keep the errorNodes list in sync with the bugReports list. 3055 HasInvalid = true; 3056 errorNodes.push_back(0); 3057 } 3058 } 3059 3060 // If all the reports have been marked invalid by a previous path generation, 3061 // we're done. 3062 if (!HasValid) 3063 return false; 3064 3065 typedef PathDiagnosticConsumer::PathGenerationScheme PathGenerationScheme; 3066 PathGenerationScheme ActiveScheme = PC.getGenerationScheme(); 3067 3068 if (ActiveScheme == PathDiagnosticConsumer::Extensive) { 3069 AnalyzerOptions &options = getAnalyzerOptions(); 3070 if (options.getBooleanOption("path-diagnostics-alternate", true)) { 3071 ActiveScheme = PathDiagnosticConsumer::AlternateExtensive; 3072 } 3073 } 3074 3075 TrimmedGraph TrimG(&getGraph(), errorNodes); 3076 ReportGraph ErrorGraph; 3077 3078 while (TrimG.popNextReportGraph(ErrorGraph)) { 3079 // Find the BugReport with the original location. 3080 assert(ErrorGraph.Index < bugReports.size()); 3081 BugReport *R = bugReports[ErrorGraph.Index]; 3082 assert(R && "No original report found for sliced graph."); 3083 assert(R->isValid() && "Report selected by trimmed graph marked invalid."); 3084 3085 // Start building the path diagnostic... 3086 PathDiagnosticBuilder PDB(*this, R, ErrorGraph.BackMap, &PC); 3087 const ExplodedNode *N = ErrorGraph.ErrorNode; 3088 3089 // Register additional node visitors. 3090 R->addVisitor(new NilReceiverBRVisitor()); 3091 R->addVisitor(new ConditionBRVisitor()); 3092 R->addVisitor(new LikelyFalsePositiveSuppressionBRVisitor()); 3093 3094 BugReport::VisitorList visitors; 3095 unsigned origReportConfigToken, finalReportConfigToken; 3096 LocationContextMap LCM; 3097 3098 // While generating diagnostics, it's possible the visitors will decide 3099 // new symbols and regions are interesting, or add other visitors based on 3100 // the information they find. If they do, we need to regenerate the path 3101 // based on our new report configuration. 3102 do { 3103 // Get a clean copy of all the visitors. 3104 for (BugReport::visitor_iterator I = R->visitor_begin(), 3105 E = R->visitor_end(); I != E; ++I) 3106 visitors.push_back((*I)->clone()); 3107 3108 // Clear out the active path from any previous work. 3109 PD.resetPath(); 3110 origReportConfigToken = R->getConfigurationChangeToken(); 3111 3112 // Generate the very last diagnostic piece - the piece is visible before 3113 // the trace is expanded. 3114 PathDiagnosticPiece *LastPiece = 0; 3115 for (BugReport::visitor_iterator I = visitors.begin(), E = visitors.end(); 3116 I != E; ++I) { 3117 if (PathDiagnosticPiece *Piece = (*I)->getEndPath(PDB, N, *R)) { 3118 assert (!LastPiece && 3119 "There can only be one final piece in a diagnostic."); 3120 LastPiece = Piece; 3121 } 3122 } 3123 3124 if (ActiveScheme != PathDiagnosticConsumer::None) { 3125 if (!LastPiece) 3126 LastPiece = BugReporterVisitor::getDefaultEndPath(PDB, N, *R); 3127 assert(LastPiece); 3128 PD.setEndOfPath(LastPiece); 3129 } 3130 3131 // Make sure we get a clean location context map so we don't 3132 // hold onto old mappings. 3133 LCM.clear(); 3134 3135 switch (ActiveScheme) { 3136 case PathDiagnosticConsumer::AlternateExtensive: 3137 GenerateAlternateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 3138 break; 3139 case PathDiagnosticConsumer::Extensive: 3140 GenerateExtensivePathDiagnostic(PD, PDB, N, LCM, visitors); 3141 break; 3142 case PathDiagnosticConsumer::Minimal: 3143 GenerateMinimalPathDiagnostic(PD, PDB, N, LCM, visitors); 3144 break; 3145 case PathDiagnosticConsumer::None: 3146 GenerateVisitorsOnlyPathDiagnostic(PD, PDB, N, visitors); 3147 break; 3148 } 3149 3150 // Clean up the visitors we used. 3151 llvm::DeleteContainerPointers(visitors); 3152 3153 // Did anything change while generating this path? 3154 finalReportConfigToken = R->getConfigurationChangeToken(); 3155 } while (finalReportConfigToken != origReportConfigToken); 3156 3157 if (!R->isValid()) 3158 continue; 3159 3160 // Finally, prune the diagnostic path of uninteresting stuff. 3161 if (!PD.path.empty()) { 3162 if (R->shouldPrunePath() && getAnalyzerOptions().shouldPrunePaths()) { 3163 bool stillHasNotes = removeUnneededCalls(PD.getMutablePieces(), R, LCM); 3164 assert(stillHasNotes); 3165 (void)stillHasNotes; 3166 } 3167 3168 // Redirect all call pieces to have valid locations. 3169 adjustCallLocations(PD.getMutablePieces()); 3170 3171 removePiecesWithInvalidLocations(PD.getMutablePieces()); 3172 3173 if (ActiveScheme == PathDiagnosticConsumer::AlternateExtensive) { 3174 SourceManager &SM = getSourceManager(); 3175 3176 // Reduce the number of edges from a very conservative set 3177 // to an aesthetically pleasing subset that conveys the 3178 // necessary information. 3179 OptimizedCallsSet OCS; 3180 while (optimizeEdges(PD.getMutablePieces(), SM, OCS, LCM)) {} 3181 3182 // Drop the very first function-entry edge. It's not really necessary 3183 // for top-level functions. 3184 dropFunctionEntryEdge(PD.getMutablePieces(), LCM, SM); 3185 } 3186 3187 // Remove messages that are basically the same. 3188 // We have to do this after edge optimization in the Extensive mode. 3189 removeRedundantMsgs(PD.getMutablePieces()); 3190 } 3191 3192 // We found a report and didn't suppress it. 3193 return true; 3194 } 3195 3196 // We suppressed all the reports in this equivalence class. 3197 assert(!HasInvalid && "Inconsistent suppression"); 3198 (void)HasInvalid; 3199 return false; 3200} 3201 3202void BugReporter::Register(BugType *BT) { 3203 BugTypes = F.add(BugTypes, BT); 3204} 3205 3206void BugReporter::emitReport(BugReport* R) { 3207 // Compute the bug report's hash to determine its equivalence class. 3208 llvm::FoldingSetNodeID ID; 3209 R->Profile(ID); 3210 3211 // Lookup the equivance class. If there isn't one, create it. 3212 BugType& BT = R->getBugType(); 3213 Register(&BT); 3214 void *InsertPos; 3215 BugReportEquivClass* EQ = EQClasses.FindNodeOrInsertPos(ID, InsertPos); 3216 3217 if (!EQ) { 3218 EQ = new BugReportEquivClass(R); 3219 EQClasses.InsertNode(EQ, InsertPos); 3220 EQClassesVector.push_back(EQ); 3221 } 3222 else 3223 EQ->AddReport(R); 3224} 3225 3226 3227//===----------------------------------------------------------------------===// 3228// Emitting reports in equivalence classes. 3229//===----------------------------------------------------------------------===// 3230 3231namespace { 3232struct FRIEC_WLItem { 3233 const ExplodedNode *N; 3234 ExplodedNode::const_succ_iterator I, E; 3235 3236 FRIEC_WLItem(const ExplodedNode *n) 3237 : N(n), I(N->succ_begin()), E(N->succ_end()) {} 3238}; 3239} 3240 3241static BugReport * 3242FindReportInEquivalenceClass(BugReportEquivClass& EQ, 3243 SmallVectorImpl<BugReport*> &bugReports) { 3244 3245 BugReportEquivClass::iterator I = EQ.begin(), E = EQ.end(); 3246 assert(I != E); 3247 BugType& BT = I->getBugType(); 3248 3249 // If we don't need to suppress any of the nodes because they are 3250 // post-dominated by a sink, simply add all the nodes in the equivalence class 3251 // to 'Nodes'. Any of the reports will serve as a "representative" report. 3252 if (!BT.isSuppressOnSink()) { 3253 BugReport *R = I; 3254 for (BugReportEquivClass::iterator I=EQ.begin(), E=EQ.end(); I!=E; ++I) { 3255 const ExplodedNode *N = I->getErrorNode(); 3256 if (N) { 3257 R = I; 3258 bugReports.push_back(R); 3259 } 3260 } 3261 return R; 3262 } 3263 3264 // For bug reports that should be suppressed when all paths are post-dominated 3265 // by a sink node, iterate through the reports in the equivalence class 3266 // until we find one that isn't post-dominated (if one exists). We use a 3267 // DFS traversal of the ExplodedGraph to find a non-sink node. We could write 3268 // this as a recursive function, but we don't want to risk blowing out the 3269 // stack for very long paths. 3270 BugReport *exampleReport = 0; 3271 3272 for (; I != E; ++I) { 3273 const ExplodedNode *errorNode = I->getErrorNode(); 3274 3275 if (!errorNode) 3276 continue; 3277 if (errorNode->isSink()) { 3278 llvm_unreachable( 3279 "BugType::isSuppressSink() should not be 'true' for sink end nodes"); 3280 } 3281 // No successors? By definition this nodes isn't post-dominated by a sink. 3282 if (errorNode->succ_empty()) { 3283 bugReports.push_back(I); 3284 if (!exampleReport) 3285 exampleReport = I; 3286 continue; 3287 } 3288 3289 // At this point we know that 'N' is not a sink and it has at least one 3290 // successor. Use a DFS worklist to find a non-sink end-of-path node. 3291 typedef FRIEC_WLItem WLItem; 3292 typedef SmallVector<WLItem, 10> DFSWorkList; 3293 llvm::DenseMap<const ExplodedNode *, unsigned> Visited; 3294 3295 DFSWorkList WL; 3296 WL.push_back(errorNode); 3297 Visited[errorNode] = 1; 3298 3299 while (!WL.empty()) { 3300 WLItem &WI = WL.back(); 3301 assert(!WI.N->succ_empty()); 3302 3303 for (; WI.I != WI.E; ++WI.I) { 3304 const ExplodedNode *Succ = *WI.I; 3305 // End-of-path node? 3306 if (Succ->succ_empty()) { 3307 // If we found an end-of-path node that is not a sink. 3308 if (!Succ->isSink()) { 3309 bugReports.push_back(I); 3310 if (!exampleReport) 3311 exampleReport = I; 3312 WL.clear(); 3313 break; 3314 } 3315 // Found a sink? Continue on to the next successor. 3316 continue; 3317 } 3318 // Mark the successor as visited. If it hasn't been explored, 3319 // enqueue it to the DFS worklist. 3320 unsigned &mark = Visited[Succ]; 3321 if (!mark) { 3322 mark = 1; 3323 WL.push_back(Succ); 3324 break; 3325 } 3326 } 3327 3328 // The worklist may have been cleared at this point. First 3329 // check if it is empty before checking the last item. 3330 if (!WL.empty() && &WL.back() == &WI) 3331 WL.pop_back(); 3332 } 3333 } 3334 3335 // ExampleReport will be NULL if all the nodes in the equivalence class 3336 // were post-dominated by sinks. 3337 return exampleReport; 3338} 3339 3340void BugReporter::FlushReport(BugReportEquivClass& EQ) { 3341 SmallVector<BugReport*, 10> bugReports; 3342 BugReport *exampleReport = FindReportInEquivalenceClass(EQ, bugReports); 3343 if (exampleReport) { 3344 const PathDiagnosticConsumers &C = getPathDiagnosticConsumers(); 3345 for (PathDiagnosticConsumers::const_iterator I=C.begin(), 3346 E=C.end(); I != E; ++I) { 3347 FlushReport(exampleReport, **I, bugReports); 3348 } 3349 } 3350} 3351 3352void BugReporter::FlushReport(BugReport *exampleReport, 3353 PathDiagnosticConsumer &PD, 3354 ArrayRef<BugReport*> bugReports) { 3355 3356 // FIXME: Make sure we use the 'R' for the path that was actually used. 3357 // Probably doesn't make a difference in practice. 3358 BugType& BT = exampleReport->getBugType(); 3359 3360 OwningPtr<PathDiagnostic> 3361 D(new PathDiagnostic(exampleReport->getDeclWithIssue(), 3362 exampleReport->getBugType().getName(), 3363 exampleReport->getDescription(), 3364 exampleReport->getShortDescription(/*Fallback=*/false), 3365 BT.getCategory(), 3366 exampleReport->getUniqueingLocation(), 3367 exampleReport->getUniqueingDecl())); 3368 3369 MaxBugClassSize = std::max(bugReports.size(), 3370 static_cast<size_t>(MaxBugClassSize)); 3371 3372 // Generate the full path diagnostic, using the generation scheme 3373 // specified by the PathDiagnosticConsumer. Note that we have to generate 3374 // path diagnostics even for consumers which do not support paths, because 3375 // the BugReporterVisitors may mark this bug as a false positive. 3376 if (!bugReports.empty()) 3377 if (!generatePathDiagnostic(*D.get(), PD, bugReports)) 3378 return; 3379 3380 MaxValidBugClassSize = std::max(bugReports.size(), 3381 static_cast<size_t>(MaxValidBugClassSize)); 3382 3383 // Examine the report and see if the last piece is in a header. Reset the 3384 // report location to the last piece in the main source file. 3385 AnalyzerOptions& Opts = getAnalyzerOptions(); 3386 if (Opts.shouldReportIssuesInMainSourceFile() && !Opts.AnalyzeAll) 3387 D->resetDiagnosticLocationToMainFile(); 3388 3389 // If the path is empty, generate a single step path with the location 3390 // of the issue. 3391 if (D->path.empty()) { 3392 PathDiagnosticLocation L = exampleReport->getLocation(getSourceManager()); 3393 PathDiagnosticPiece *piece = 3394 new PathDiagnosticEventPiece(L, exampleReport->getDescription()); 3395 BugReport::ranges_iterator Beg, End; 3396 llvm::tie(Beg, End) = exampleReport->getRanges(); 3397 for ( ; Beg != End; ++Beg) 3398 piece->addRange(*Beg); 3399 D->setEndOfPath(piece); 3400 } 3401 3402 // Get the meta data. 3403 const BugReport::ExtraTextList &Meta = exampleReport->getExtraText(); 3404 for (BugReport::ExtraTextList::const_iterator i = Meta.begin(), 3405 e = Meta.end(); i != e; ++i) { 3406 D->addMeta(*i); 3407 } 3408 3409 PD.HandlePathDiagnostic(D.take()); 3410} 3411 3412void BugReporter::EmitBasicReport(const Decl *DeclWithIssue, 3413 StringRef name, 3414 StringRef category, 3415 StringRef str, PathDiagnosticLocation Loc, 3416 SourceRange* RBeg, unsigned NumRanges) { 3417 3418 // 'BT' is owned by BugReporter. 3419 BugType *BT = getBugTypeForName(name, category); 3420 BugReport *R = new BugReport(*BT, str, Loc); 3421 R->setDeclWithIssue(DeclWithIssue); 3422 for ( ; NumRanges > 0 ; --NumRanges, ++RBeg) R->addRange(*RBeg); 3423 emitReport(R); 3424} 3425 3426BugType *BugReporter::getBugTypeForName(StringRef name, 3427 StringRef category) { 3428 SmallString<136> fullDesc; 3429 llvm::raw_svector_ostream(fullDesc) << name << ":" << category; 3430 llvm::StringMapEntry<BugType *> & 3431 entry = StrBugTypes.GetOrCreateValue(fullDesc); 3432 BugType *BT = entry.getValue(); 3433 if (!BT) { 3434 BT = new BugType(name, category); 3435 entry.setValue(BT); 3436 } 3437 return BT; 3438} 3439 3440 3441void PathPieces::dump() const { 3442 unsigned index = 0; 3443 for (PathPieces::const_iterator I = begin(), E = end(); I != E; ++I) { 3444 llvm::errs() << "[" << index++ << "] "; 3445 (*I)->dump(); 3446 llvm::errs() << "\n"; 3447 } 3448} 3449 3450void PathDiagnosticCallPiece::dump() const { 3451 llvm::errs() << "CALL\n--------------\n"; 3452 3453 if (const Stmt *SLoc = getLocStmt(getLocation())) 3454 SLoc->dump(); 3455 else if (const NamedDecl *ND = dyn_cast<NamedDecl>(getCallee())) 3456 llvm::errs() << *ND << "\n"; 3457 else 3458 getLocation().dump(); 3459} 3460 3461void PathDiagnosticEventPiece::dump() const { 3462 llvm::errs() << "EVENT\n--------------\n"; 3463 llvm::errs() << getString() << "\n"; 3464 llvm::errs() << " ---- at ----\n"; 3465 getLocation().dump(); 3466} 3467 3468void PathDiagnosticControlFlowPiece::dump() const { 3469 llvm::errs() << "CONTROL\n--------------\n"; 3470 getStartLocation().dump(); 3471 llvm::errs() << " ---- to ----\n"; 3472 getEndLocation().dump(); 3473} 3474 3475void PathDiagnosticMacroPiece::dump() const { 3476 llvm::errs() << "MACRO\n--------------\n"; 3477 // FIXME: Print which macro is being invoked. 3478} 3479 3480void PathDiagnosticLocation::dump() const { 3481 if (!isValid()) { 3482 llvm::errs() << "<INVALID>\n"; 3483 return; 3484 } 3485 3486 switch (K) { 3487 case RangeK: 3488 // FIXME: actually print the range. 3489 llvm::errs() << "<range>\n"; 3490 break; 3491 case SingleLocK: 3492 asLocation().dump(); 3493 llvm::errs() << "\n"; 3494 break; 3495 case StmtK: 3496 if (S) 3497 S->dump(); 3498 else 3499 llvm::errs() << "<NULL STMT>\n"; 3500 break; 3501 case DeclK: 3502 if (const NamedDecl *ND = dyn_cast_or_null<NamedDecl>(D)) 3503 llvm::errs() << *ND << "\n"; 3504 else if (isa<BlockDecl>(D)) 3505 // FIXME: Make this nicer. 3506 llvm::errs() << "<block>\n"; 3507 else if (D) 3508 llvm::errs() << "<unknown decl>\n"; 3509 else 3510 llvm::errs() << "<NULL DECL>\n"; 3511 break; 3512 } 3513} 3514