1 //===- CoreEngine.cpp - Path-Sensitive Dataflow Engine --------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file defines a generic engine for intraprocedural, path-sensitive, 10 // dataflow analysis via graph reachability engine. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h" 15 #include "clang/AST/Expr.h" 16 #include "clang/AST/ExprCXX.h" 17 #include "clang/AST/Stmt.h" 18 #include "clang/AST/StmtCXX.h" 19 #include "clang/Analysis/AnalysisDeclContext.h" 20 #include "clang/Analysis/CFG.h" 21 #include "clang/Analysis/ProgramPoint.h" 22 #include "clang/Basic/LLVM.h" 23 #include "clang/StaticAnalyzer/Core/AnalyzerOptions.h" 24 #include "clang/StaticAnalyzer/Core/PathSensitive/BlockCounter.h" 25 #include "clang/StaticAnalyzer/Core/PathSensitive/ExplodedGraph.h" 26 #include "clang/StaticAnalyzer/Core/PathSensitive/ExprEngine.h" 27 #include "clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h" 28 #include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h" 29 #include "llvm/ADT/STLExtras.h" 30 #include "llvm/ADT/Statistic.h" 31 #include "llvm/Support/Casting.h" 32 #include "llvm/Support/ErrorHandling.h" 33 #include <algorithm> 34 #include <cassert> 35 #include <memory> 36 #include <optional> 37 #include <utility> 38 39 using namespace clang; 40 using namespace ento; 41 42 #define DEBUG_TYPE "CoreEngine" 43 44 STATISTIC(NumSteps, 45 "The # of steps executed."); 46 STATISTIC(NumSTUSteps, "The # of STU steps executed."); 47 STATISTIC(NumCTUSteps, "The # of CTU steps executed."); 48 STATISTIC(NumReachedMaxSteps, 49 "The # of times we reached the max number of steps."); 50 STATISTIC(NumPathsExplored, 51 "The # of paths explored by the analyzer."); 52 53 //===----------------------------------------------------------------------===// 54 // Core analysis engine. 55 //===----------------------------------------------------------------------===// 56 57 static std::unique_ptr<WorkList> generateWorkList(AnalyzerOptions &Opts) { 58 switch (Opts.getExplorationStrategy()) { 59 case ExplorationStrategyKind::DFS: 60 return WorkList::makeDFS(); 61 case ExplorationStrategyKind::BFS: 62 return WorkList::makeBFS(); 63 case ExplorationStrategyKind::BFSBlockDFSContents: 64 return WorkList::makeBFSBlockDFSContents(); 65 case ExplorationStrategyKind::UnexploredFirst: 66 return WorkList::makeUnexploredFirst(); 67 case ExplorationStrategyKind::UnexploredFirstQueue: 68 return WorkList::makeUnexploredFirstPriorityQueue(); 69 case ExplorationStrategyKind::UnexploredFirstLocationQueue: 70 return WorkList::makeUnexploredFirstPriorityLocationQueue(); 71 } 72 llvm_unreachable("Unknown AnalyzerOptions::ExplorationStrategyKind"); 73 } 74 75 CoreEngine::CoreEngine(ExprEngine &exprengine, FunctionSummariesTy *FS, 76 AnalyzerOptions &Opts) 77 : ExprEng(exprengine), WList(generateWorkList(Opts)), 78 CTUWList(Opts.IsNaiveCTUEnabled ? generateWorkList(Opts) : nullptr), 79 BCounterFactory(G.getAllocator()), FunctionSummaries(FS) {} 80 81 void CoreEngine::setBlockCounter(BlockCounter C) { 82 WList->setBlockCounter(C); 83 if (CTUWList) 84 CTUWList->setBlockCounter(C); 85 } 86 87 /// ExecuteWorkList - Run the worklist algorithm for a maximum number of steps. 88 bool CoreEngine::ExecuteWorkList(const LocationContext *L, unsigned MaxSteps, 89 ProgramStateRef InitState) { 90 if (G.num_roots() == 0) { // Initialize the analysis by constructing 91 // the root if none exists. 92 93 const CFGBlock *Entry = &(L->getCFG()->getEntry()); 94 95 assert(Entry->empty() && "Entry block must be empty."); 96 97 assert(Entry->succ_size() == 1 && "Entry block must have 1 successor."); 98 99 // Mark the entry block as visited. 100 FunctionSummaries->markVisitedBasicBlock(Entry->getBlockID(), 101 L->getDecl(), 102 L->getCFG()->getNumBlockIDs()); 103 104 // Get the solitary successor. 105 const CFGBlock *Succ = *(Entry->succ_begin()); 106 107 // Construct an edge representing the 108 // starting location in the function. 109 BlockEdge StartLoc(Entry, Succ, L); 110 111 // Set the current block counter to being empty. 112 setBlockCounter(BCounterFactory.GetEmptyCounter()); 113 114 if (!InitState) 115 InitState = ExprEng.getInitialState(L); 116 117 bool IsNew; 118 ExplodedNode *Node = G.getNode(StartLoc, InitState, false, &IsNew); 119 assert(IsNew); 120 G.addRoot(Node); 121 122 NodeBuilderContext BuilderCtx(*this, StartLoc.getDst(), Node); 123 ExplodedNodeSet DstBegin; 124 ExprEng.processBeginOfFunction(BuilderCtx, Node, DstBegin, StartLoc); 125 126 enqueue(DstBegin); 127 } 128 129 // Check if we have a steps limit 130 bool UnlimitedSteps = MaxSteps == 0; 131 132 // Cap our pre-reservation in the event that the user specifies 133 // a very large number of maximum steps. 134 const unsigned PreReservationCap = 4000000; 135 if(!UnlimitedSteps) 136 G.reserve(std::min(MaxSteps, PreReservationCap)); 137 138 auto ProcessWList = [this, UnlimitedSteps](unsigned MaxSteps) { 139 unsigned Steps = MaxSteps; 140 while (WList->hasWork()) { 141 if (!UnlimitedSteps) { 142 if (Steps == 0) { 143 NumReachedMaxSteps++; 144 break; 145 } 146 --Steps; 147 } 148 149 NumSteps++; 150 151 const WorkListUnit &WU = WList->dequeue(); 152 153 // Set the current block counter. 154 setBlockCounter(WU.getBlockCounter()); 155 156 // Retrieve the node. 157 ExplodedNode *Node = WU.getNode(); 158 159 dispatchWorkItem(Node, Node->getLocation(), WU); 160 } 161 return MaxSteps - Steps; 162 }; 163 const unsigned STUSteps = ProcessWList(MaxSteps); 164 165 if (CTUWList) { 166 NumSTUSteps += STUSteps; 167 const unsigned MinCTUSteps = 168 this->ExprEng.getAnalysisManager().options.CTUMaxNodesMin; 169 const unsigned Pct = 170 this->ExprEng.getAnalysisManager().options.CTUMaxNodesPercentage; 171 unsigned MaxCTUSteps = std::max(STUSteps * Pct / 100, MinCTUSteps); 172 173 WList = std::move(CTUWList); 174 const unsigned CTUSteps = ProcessWList(MaxCTUSteps); 175 NumCTUSteps += CTUSteps; 176 } 177 178 ExprEng.processEndWorklist(); 179 return WList->hasWork(); 180 } 181 182 void CoreEngine::dispatchWorkItem(ExplodedNode* Pred, ProgramPoint Loc, 183 const WorkListUnit& WU) { 184 // Dispatch on the location type. 185 switch (Loc.getKind()) { 186 case ProgramPoint::BlockEdgeKind: 187 HandleBlockEdge(Loc.castAs<BlockEdge>(), Pred); 188 break; 189 190 case ProgramPoint::BlockEntranceKind: 191 HandleBlockEntrance(Loc.castAs<BlockEntrance>(), Pred); 192 break; 193 194 case ProgramPoint::BlockExitKind: 195 assert(false && "BlockExit location never occur in forward analysis."); 196 break; 197 198 case ProgramPoint::CallEnterKind: 199 HandleCallEnter(Loc.castAs<CallEnter>(), Pred); 200 break; 201 202 case ProgramPoint::CallExitBeginKind: 203 ExprEng.processCallExit(Pred); 204 break; 205 206 case ProgramPoint::EpsilonKind: { 207 assert(Pred->hasSinglePred() && 208 "Assume epsilon has exactly one predecessor by construction"); 209 ExplodedNode *PNode = Pred->getFirstPred(); 210 dispatchWorkItem(Pred, PNode->getLocation(), WU); 211 break; 212 } 213 default: 214 assert(Loc.getAs<PostStmt>() || 215 Loc.getAs<PostInitializer>() || 216 Loc.getAs<PostImplicitCall>() || 217 Loc.getAs<CallExitEnd>() || 218 Loc.getAs<LoopExit>() || 219 Loc.getAs<PostAllocatorCall>()); 220 HandlePostStmt(WU.getBlock(), WU.getIndex(), Pred); 221 break; 222 } 223 } 224 225 bool CoreEngine::ExecuteWorkListWithInitialState(const LocationContext *L, 226 unsigned Steps, 227 ProgramStateRef InitState, 228 ExplodedNodeSet &Dst) { 229 bool DidNotFinish = ExecuteWorkList(L, Steps, InitState); 230 for (ExplodedGraph::eop_iterator I = G.eop_begin(), E = G.eop_end(); I != E; 231 ++I) { 232 Dst.Add(*I); 233 } 234 return DidNotFinish; 235 } 236 237 void CoreEngine::HandleBlockEdge(const BlockEdge &L, ExplodedNode *Pred) { 238 const CFGBlock *Blk = L.getDst(); 239 NodeBuilderContext BuilderCtx(*this, Blk, Pred); 240 241 // Mark this block as visited. 242 const LocationContext *LC = Pred->getLocationContext(); 243 FunctionSummaries->markVisitedBasicBlock(Blk->getBlockID(), 244 LC->getDecl(), 245 LC->getCFG()->getNumBlockIDs()); 246 247 // Display a prunable path note to the user if it's a virtual bases branch 248 // and we're taking the path that skips virtual base constructors. 249 if (L.getSrc()->getTerminator().isVirtualBaseBranch() && 250 L.getDst() == *L.getSrc()->succ_begin()) { 251 ProgramPoint P = L.withTag(getDataTags().make<NoteTag>( 252 [](BugReporterContext &, PathSensitiveBugReport &) -> std::string { 253 // TODO: Just call out the name of the most derived class 254 // when we know it. 255 return "Virtual base initialization skipped because " 256 "it has already been handled by the most derived class"; 257 }, 258 /*IsPrunable=*/true)); 259 // Perform the transition. 260 ExplodedNodeSet Dst; 261 NodeBuilder Bldr(Pred, Dst, BuilderCtx); 262 Pred = Bldr.generateNode(P, Pred->getState(), Pred); 263 if (!Pred) 264 return; 265 } 266 267 // Check if we are entering the EXIT block. 268 if (Blk == &(L.getLocationContext()->getCFG()->getExit())) { 269 assert(L.getLocationContext()->getCFG()->getExit().empty() && 270 "EXIT block cannot contain Stmts."); 271 272 // Get return statement.. 273 const ReturnStmt *RS = nullptr; 274 if (!L.getSrc()->empty()) { 275 CFGElement LastElement = L.getSrc()->back(); 276 if (std::optional<CFGStmt> LastStmt = LastElement.getAs<CFGStmt>()) { 277 RS = dyn_cast<ReturnStmt>(LastStmt->getStmt()); 278 } else if (std::optional<CFGAutomaticObjDtor> AutoDtor = 279 LastElement.getAs<CFGAutomaticObjDtor>()) { 280 RS = dyn_cast<ReturnStmt>(AutoDtor->getTriggerStmt()); 281 } 282 } 283 284 // Process the final state transition. 285 ExprEng.processEndOfFunction(BuilderCtx, Pred, RS); 286 287 // This path is done. Don't enqueue any more nodes. 288 return; 289 } 290 291 // Call into the ExprEngine to process entering the CFGBlock. 292 ExplodedNodeSet dstNodes; 293 BlockEntrance BE(Blk, Pred->getLocationContext()); 294 NodeBuilderWithSinks nodeBuilder(Pred, dstNodes, BuilderCtx, BE); 295 ExprEng.processCFGBlockEntrance(L, nodeBuilder, Pred); 296 297 // Auto-generate a node. 298 if (!nodeBuilder.hasGeneratedNodes()) { 299 nodeBuilder.generateNode(Pred->State, Pred); 300 } 301 302 // Enqueue nodes onto the worklist. 303 enqueue(dstNodes); 304 } 305 306 void CoreEngine::HandleBlockEntrance(const BlockEntrance &L, 307 ExplodedNode *Pred) { 308 // Increment the block counter. 309 const LocationContext *LC = Pred->getLocationContext(); 310 unsigned BlockId = L.getBlock()->getBlockID(); 311 BlockCounter Counter = WList->getBlockCounter(); 312 Counter = BCounterFactory.IncrementCount(Counter, LC->getStackFrame(), 313 BlockId); 314 setBlockCounter(Counter); 315 316 // Process the entrance of the block. 317 if (std::optional<CFGElement> E = L.getFirstElement()) { 318 NodeBuilderContext Ctx(*this, L.getBlock(), Pred); 319 ExprEng.processCFGElement(*E, Pred, 0, &Ctx); 320 } else 321 HandleBlockExit(L.getBlock(), Pred); 322 } 323 324 void CoreEngine::HandleBlockExit(const CFGBlock * B, ExplodedNode *Pred) { 325 if (const Stmt *Term = B->getTerminatorStmt()) { 326 switch (Term->getStmtClass()) { 327 default: 328 llvm_unreachable("Analysis for this terminator not implemented."); 329 330 case Stmt::CXXBindTemporaryExprClass: 331 HandleCleanupTemporaryBranch( 332 cast<CXXBindTemporaryExpr>(Term), B, Pred); 333 return; 334 335 // Model static initializers. 336 case Stmt::DeclStmtClass: 337 HandleStaticInit(cast<DeclStmt>(Term), B, Pred); 338 return; 339 340 case Stmt::BinaryOperatorClass: // '&&' and '||' 341 HandleBranch(cast<BinaryOperator>(Term)->getLHS(), Term, B, Pred); 342 return; 343 344 case Stmt::BinaryConditionalOperatorClass: 345 case Stmt::ConditionalOperatorClass: 346 HandleBranch(cast<AbstractConditionalOperator>(Term)->getCond(), 347 Term, B, Pred); 348 return; 349 350 // FIXME: Use constant-folding in CFG construction to simplify this 351 // case. 352 353 case Stmt::ChooseExprClass: 354 HandleBranch(cast<ChooseExpr>(Term)->getCond(), Term, B, Pred); 355 return; 356 357 case Stmt::CXXTryStmtClass: 358 // Generate a node for each of the successors. 359 // Our logic for EH analysis can certainly be improved. 360 for (CFGBlock::const_succ_iterator it = B->succ_begin(), 361 et = B->succ_end(); it != et; ++it) { 362 if (const CFGBlock *succ = *it) { 363 generateNode(BlockEdge(B, succ, Pred->getLocationContext()), 364 Pred->State, Pred); 365 } 366 } 367 return; 368 369 case Stmt::DoStmtClass: 370 HandleBranch(cast<DoStmt>(Term)->getCond(), Term, B, Pred); 371 return; 372 373 case Stmt::CXXForRangeStmtClass: 374 HandleBranch(cast<CXXForRangeStmt>(Term)->getCond(), Term, B, Pred); 375 return; 376 377 case Stmt::ForStmtClass: 378 HandleBranch(cast<ForStmt>(Term)->getCond(), Term, B, Pred); 379 return; 380 381 case Stmt::SEHLeaveStmtClass: 382 case Stmt::ContinueStmtClass: 383 case Stmt::BreakStmtClass: 384 case Stmt::GotoStmtClass: 385 break; 386 387 case Stmt::IfStmtClass: 388 HandleBranch(cast<IfStmt>(Term)->getCond(), Term, B, Pred); 389 return; 390 391 case Stmt::IndirectGotoStmtClass: { 392 // Only 1 successor: the indirect goto dispatch block. 393 assert(B->succ_size() == 1); 394 395 IndirectGotoNodeBuilder 396 builder(Pred, B, cast<IndirectGotoStmt>(Term)->getTarget(), 397 *(B->succ_begin()), this); 398 399 ExprEng.processIndirectGoto(builder); 400 return; 401 } 402 403 case Stmt::ObjCForCollectionStmtClass: 404 // In the case of ObjCForCollectionStmt, it appears twice in a CFG: 405 // 406 // (1) inside a basic block, which represents the binding of the 407 // 'element' variable to a value. 408 // (2) in a terminator, which represents the branch. 409 // 410 // For (1), ExprEngine will bind a value (i.e., 0 or 1) indicating 411 // whether or not collection contains any more elements. We cannot 412 // just test to see if the element is nil because a container can 413 // contain nil elements. 414 HandleBranch(Term, Term, B, Pred); 415 return; 416 417 case Stmt::SwitchStmtClass: { 418 SwitchNodeBuilder builder(Pred, B, cast<SwitchStmt>(Term)->getCond(), 419 this); 420 421 ExprEng.processSwitch(builder); 422 return; 423 } 424 425 case Stmt::WhileStmtClass: 426 HandleBranch(cast<WhileStmt>(Term)->getCond(), Term, B, Pred); 427 return; 428 429 case Stmt::GCCAsmStmtClass: 430 assert(cast<GCCAsmStmt>(Term)->isAsmGoto() && "Encountered GCCAsmStmt without labels"); 431 // TODO: Handle jumping to labels 432 return; 433 } 434 } 435 436 if (B->getTerminator().isVirtualBaseBranch()) { 437 HandleVirtualBaseBranch(B, Pred); 438 return; 439 } 440 441 assert(B->succ_size() == 1 && 442 "Blocks with no terminator should have at most 1 successor."); 443 444 generateNode(BlockEdge(B, *(B->succ_begin()), Pred->getLocationContext()), 445 Pred->State, Pred); 446 } 447 448 void CoreEngine::HandleCallEnter(const CallEnter &CE, ExplodedNode *Pred) { 449 NodeBuilderContext BuilderCtx(*this, CE.getEntry(), Pred); 450 ExprEng.processCallEnter(BuilderCtx, CE, Pred); 451 } 452 453 void CoreEngine::HandleBranch(const Stmt *Cond, const Stmt *Term, 454 const CFGBlock * B, ExplodedNode *Pred) { 455 assert(B->succ_size() == 2); 456 NodeBuilderContext Ctx(*this, B, Pred); 457 ExplodedNodeSet Dst; 458 ExprEng.processBranch(Cond, Ctx, Pred, Dst, *(B->succ_begin()), 459 *(B->succ_begin() + 1)); 460 // Enqueue the new frontier onto the worklist. 461 enqueue(Dst); 462 } 463 464 void CoreEngine::HandleCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE, 465 const CFGBlock *B, 466 ExplodedNode *Pred) { 467 assert(B->succ_size() == 2); 468 NodeBuilderContext Ctx(*this, B, Pred); 469 ExplodedNodeSet Dst; 470 ExprEng.processCleanupTemporaryBranch(BTE, Ctx, Pred, Dst, *(B->succ_begin()), 471 *(B->succ_begin() + 1)); 472 // Enqueue the new frontier onto the worklist. 473 enqueue(Dst); 474 } 475 476 void CoreEngine::HandleStaticInit(const DeclStmt *DS, const CFGBlock *B, 477 ExplodedNode *Pred) { 478 assert(B->succ_size() == 2); 479 NodeBuilderContext Ctx(*this, B, Pred); 480 ExplodedNodeSet Dst; 481 ExprEng.processStaticInitializer(DS, Ctx, Pred, Dst, 482 *(B->succ_begin()), *(B->succ_begin()+1)); 483 // Enqueue the new frontier onto the worklist. 484 enqueue(Dst); 485 } 486 487 void CoreEngine::HandlePostStmt(const CFGBlock *B, unsigned StmtIdx, 488 ExplodedNode *Pred) { 489 assert(B); 490 assert(!B->empty()); 491 492 if (StmtIdx == B->size()) 493 HandleBlockExit(B, Pred); 494 else { 495 NodeBuilderContext Ctx(*this, B, Pred); 496 ExprEng.processCFGElement((*B)[StmtIdx], Pred, StmtIdx, &Ctx); 497 } 498 } 499 500 void CoreEngine::HandleVirtualBaseBranch(const CFGBlock *B, 501 ExplodedNode *Pred) { 502 const LocationContext *LCtx = Pred->getLocationContext(); 503 if (const auto *CallerCtor = dyn_cast_or_null<CXXConstructExpr>( 504 LCtx->getStackFrame()->getCallSite())) { 505 switch (CallerCtor->getConstructionKind()) { 506 case CXXConstructExpr::CK_NonVirtualBase: 507 case CXXConstructExpr::CK_VirtualBase: { 508 BlockEdge Loc(B, *B->succ_begin(), LCtx); 509 HandleBlockEdge(Loc, Pred); 510 return; 511 } 512 default: 513 break; 514 } 515 } 516 517 // We either don't see a parent stack frame because we're in the top frame, 518 // or the parent stack frame doesn't initialize our virtual bases. 519 BlockEdge Loc(B, *(B->succ_begin() + 1), LCtx); 520 HandleBlockEdge(Loc, Pred); 521 } 522 523 /// generateNode - Utility method to generate nodes, hook up successors, 524 /// and add nodes to the worklist. 525 void CoreEngine::generateNode(const ProgramPoint &Loc, 526 ProgramStateRef State, 527 ExplodedNode *Pred) { 528 bool IsNew; 529 ExplodedNode *Node = G.getNode(Loc, State, false, &IsNew); 530 531 if (Pred) 532 Node->addPredecessor(Pred, G); // Link 'Node' with its predecessor. 533 else { 534 assert(IsNew); 535 G.addRoot(Node); // 'Node' has no predecessor. Make it a root. 536 } 537 538 // Only add 'Node' to the worklist if it was freshly generated. 539 if (IsNew) WList->enqueue(Node); 540 } 541 542 void CoreEngine::enqueueStmtNode(ExplodedNode *N, 543 const CFGBlock *Block, unsigned Idx) { 544 assert(Block); 545 assert(!N->isSink()); 546 547 // Check if this node entered a callee. 548 if (N->getLocation().getAs<CallEnter>()) { 549 // Still use the index of the CallExpr. It's needed to create the callee 550 // StackFrameContext. 551 WList->enqueue(N, Block, Idx); 552 return; 553 } 554 555 // Do not create extra nodes. Move to the next CFG element. 556 if (N->getLocation().getAs<PostInitializer>() || 557 N->getLocation().getAs<PostImplicitCall>()|| 558 N->getLocation().getAs<LoopExit>()) { 559 WList->enqueue(N, Block, Idx+1); 560 return; 561 } 562 563 if (N->getLocation().getAs<EpsilonPoint>()) { 564 WList->enqueue(N, Block, Idx); 565 return; 566 } 567 568 if ((*Block)[Idx].getKind() == CFGElement::NewAllocator) { 569 WList->enqueue(N, Block, Idx+1); 570 return; 571 } 572 573 // At this point, we know we're processing a normal statement. 574 CFGStmt CS = (*Block)[Idx].castAs<CFGStmt>(); 575 PostStmt Loc(CS.getStmt(), N->getLocationContext()); 576 577 if (Loc == N->getLocation().withTag(nullptr)) { 578 // Note: 'N' should be a fresh node because otherwise it shouldn't be 579 // a member of Deferred. 580 WList->enqueue(N, Block, Idx+1); 581 return; 582 } 583 584 bool IsNew; 585 ExplodedNode *Succ = G.getNode(Loc, N->getState(), false, &IsNew); 586 Succ->addPredecessor(N, G); 587 588 if (IsNew) 589 WList->enqueue(Succ, Block, Idx+1); 590 } 591 592 ExplodedNode *CoreEngine::generateCallExitBeginNode(ExplodedNode *N, 593 const ReturnStmt *RS) { 594 // Create a CallExitBegin node and enqueue it. 595 const auto *LocCtx = cast<StackFrameContext>(N->getLocationContext()); 596 597 // Use the callee location context. 598 CallExitBegin Loc(LocCtx, RS); 599 600 bool isNew; 601 ExplodedNode *Node = G.getNode(Loc, N->getState(), false, &isNew); 602 Node->addPredecessor(N, G); 603 return isNew ? Node : nullptr; 604 } 605 606 void CoreEngine::enqueue(ExplodedNodeSet &Set) { 607 for (const auto I : Set) 608 WList->enqueue(I); 609 } 610 611 void CoreEngine::enqueue(ExplodedNodeSet &Set, 612 const CFGBlock *Block, unsigned Idx) { 613 for (const auto I : Set) 614 enqueueStmtNode(I, Block, Idx); 615 } 616 617 void CoreEngine::enqueueEndOfFunction(ExplodedNodeSet &Set, const ReturnStmt *RS) { 618 for (auto *I : Set) { 619 // If we are in an inlined call, generate CallExitBegin node. 620 if (I->getLocationContext()->getParent()) { 621 I = generateCallExitBeginNode(I, RS); 622 if (I) 623 WList->enqueue(I); 624 } else { 625 // TODO: We should run remove dead bindings here. 626 G.addEndOfPath(I); 627 NumPathsExplored++; 628 } 629 } 630 } 631 632 void NodeBuilder::anchor() {} 633 634 ExplodedNode* NodeBuilder::generateNodeImpl(const ProgramPoint &Loc, 635 ProgramStateRef State, 636 ExplodedNode *FromN, 637 bool MarkAsSink) { 638 HasGeneratedNodes = true; 639 bool IsNew; 640 ExplodedNode *N = C.Eng.G.getNode(Loc, State, MarkAsSink, &IsNew); 641 N->addPredecessor(FromN, C.Eng.G); 642 Frontier.erase(FromN); 643 644 if (!IsNew) 645 return nullptr; 646 647 if (!MarkAsSink) 648 Frontier.Add(N); 649 650 return N; 651 } 652 653 void NodeBuilderWithSinks::anchor() {} 654 655 StmtNodeBuilder::~StmtNodeBuilder() { 656 if (EnclosingBldr) 657 for (const auto I : Frontier) 658 EnclosingBldr->addNodes(I); 659 } 660 661 void BranchNodeBuilder::anchor() {} 662 663 ExplodedNode *BranchNodeBuilder::generateNode(ProgramStateRef State, 664 bool branch, 665 ExplodedNode *NodePred) { 666 // If the branch has been marked infeasible we should not generate a node. 667 if (!isFeasible(branch)) 668 return nullptr; 669 670 ProgramPoint Loc = BlockEdge(C.Block, branch ? DstT:DstF, 671 NodePred->getLocationContext()); 672 ExplodedNode *Succ = generateNodeImpl(Loc, State, NodePred); 673 return Succ; 674 } 675 676 ExplodedNode* 677 IndirectGotoNodeBuilder::generateNode(const iterator &I, 678 ProgramStateRef St, 679 bool IsSink) { 680 bool IsNew; 681 ExplodedNode *Succ = 682 Eng.G.getNode(BlockEdge(Src, I.getBlock(), Pred->getLocationContext()), 683 St, IsSink, &IsNew); 684 Succ->addPredecessor(Pred, Eng.G); 685 686 if (!IsNew) 687 return nullptr; 688 689 if (!IsSink) 690 Eng.WList->enqueue(Succ); 691 692 return Succ; 693 } 694 695 ExplodedNode* 696 SwitchNodeBuilder::generateCaseStmtNode(const iterator &I, 697 ProgramStateRef St) { 698 bool IsNew; 699 ExplodedNode *Succ = 700 Eng.G.getNode(BlockEdge(Src, I.getBlock(), Pred->getLocationContext()), 701 St, false, &IsNew); 702 Succ->addPredecessor(Pred, Eng.G); 703 if (!IsNew) 704 return nullptr; 705 706 Eng.WList->enqueue(Succ); 707 return Succ; 708 } 709 710 ExplodedNode* 711 SwitchNodeBuilder::generateDefaultCaseNode(ProgramStateRef St, 712 bool IsSink) { 713 // Get the block for the default case. 714 assert(Src->succ_rbegin() != Src->succ_rend()); 715 CFGBlock *DefaultBlock = *Src->succ_rbegin(); 716 717 // Basic correctness check for default blocks that are unreachable and not 718 // caught by earlier stages. 719 if (!DefaultBlock) 720 return nullptr; 721 722 bool IsNew; 723 ExplodedNode *Succ = 724 Eng.G.getNode(BlockEdge(Src, DefaultBlock, Pred->getLocationContext()), 725 St, IsSink, &IsNew); 726 Succ->addPredecessor(Pred, Eng.G); 727 728 if (!IsNew) 729 return nullptr; 730 731 if (!IsSink) 732 Eng.WList->enqueue(Succ); 733 734 return Succ; 735 } 736