1 //===- ExprEngine.h - Path-Sensitive Expression-Level Dataflow --*- C++ -*-===// 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 meta-engine for path-sensitive dataflow analysis that 10 // is built on CoreEngine, but provides the boilerplate to execute transfer 11 // functions and build the ExplodedGraph at the expression level. 12 // 13 //===----------------------------------------------------------------------===// 14 15 #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H 16 #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H 17 18 #include "clang/AST/Expr.h" 19 #include "clang/AST/Type.h" 20 #include "clang/Analysis/CFG.h" 21 #include "clang/Analysis/DomainSpecific/ObjCNoReturn.h" 22 #include "clang/Analysis/ProgramPoint.h" 23 #include "clang/Basic/LLVM.h" 24 #include "clang/StaticAnalyzer/Core/CheckerManager.h" 25 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 26 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h" 27 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" 28 #include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h" 29 #include "clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h" 30 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 31 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 32 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h" 33 #include "clang/StaticAnalyzer/Core/PathSensitive/Store.h" 34 #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h" 35 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h" 36 #include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h" 37 #include "llvm/ADT/ArrayRef.h" 38 #include <cassert> 39 #include <optional> 40 #include <utility> 41 42 namespace clang { 43 44 class AnalysisDeclContextManager; 45 class AnalyzerOptions; 46 class ASTContext; 47 class CFGBlock; 48 class CFGElement; 49 class ConstructionContext; 50 class CXXBindTemporaryExpr; 51 class CXXCatchStmt; 52 class CXXConstructExpr; 53 class CXXDeleteExpr; 54 class CXXNewExpr; 55 class CXXThisExpr; 56 class Decl; 57 class DeclStmt; 58 class GCCAsmStmt; 59 class LambdaExpr; 60 class LocationContext; 61 class MaterializeTemporaryExpr; 62 class MSAsmStmt; 63 class NamedDecl; 64 class ObjCAtSynchronizedStmt; 65 class ObjCForCollectionStmt; 66 class ObjCIvarRefExpr; 67 class ObjCMessageExpr; 68 class ReturnStmt; 69 class Stmt; 70 71 namespace cross_tu { 72 73 class CrossTranslationUnitContext; 74 75 } // namespace cross_tu 76 77 namespace ento { 78 79 class AnalysisManager; 80 class BasicValueFactory; 81 class CallEvent; 82 class CheckerManager; 83 class ConstraintManager; 84 class ExplodedNodeSet; 85 class ExplodedNode; 86 class IndirectGotoNodeBuilder; 87 class MemRegion; 88 class NodeBuilderContext; 89 class NodeBuilderWithSinks; 90 class ProgramState; 91 class ProgramStateManager; 92 class RegionAndSymbolInvalidationTraits; 93 class SymbolManager; 94 class SwitchNodeBuilder; 95 96 /// Hints for figuring out of a call should be inlined during evalCall(). 97 struct EvalCallOptions { 98 /// This call is a constructor or a destructor for which we do not currently 99 /// compute the this-region correctly. 100 bool IsCtorOrDtorWithImproperlyModeledTargetRegion = false; 101 102 /// This call is a constructor or a destructor for a single element within 103 /// an array, a part of array construction or destruction. 104 bool IsArrayCtorOrDtor = false; 105 106 /// This call is a constructor or a destructor of a temporary value. 107 bool IsTemporaryCtorOrDtor = false; 108 109 /// This call is a constructor for a temporary that is lifetime-extended 110 /// by binding it to a reference-type field within an aggregate, 111 /// for example 'A { const C &c; }; A a = { C() };' 112 bool IsTemporaryLifetimeExtendedViaAggregate = false; 113 114 /// This call is a pre-C++17 elidable constructor that we failed to elide 115 /// because we failed to compute the target region into which 116 /// this constructor would have been ultimately elided. Analysis that 117 /// we perform in this case is still correct but it behaves differently, 118 /// as if copy elision is disabled. 119 bool IsElidableCtorThatHasNotBeenElided = false; 120 EvalCallOptionsEvalCallOptions121 EvalCallOptions() {} 122 }; 123 124 class ExprEngine { 125 void anchor(); 126 127 public: 128 /// The modes of inlining, which override the default analysis-wide settings. 129 enum InliningModes { 130 /// Follow the default settings for inlining callees. 131 Inline_Regular = 0, 132 133 /// Do minimal inlining of callees. 134 Inline_Minimal = 0x1 135 }; 136 137 private: 138 cross_tu::CrossTranslationUnitContext &CTU; 139 bool IsCTUEnabled; 140 141 AnalysisManager &AMgr; 142 143 AnalysisDeclContextManager &AnalysisDeclContexts; 144 145 CoreEngine Engine; 146 147 /// G - the simulation graph. 148 ExplodedGraph &G; 149 150 /// StateMgr - Object that manages the data for all created states. 151 ProgramStateManager StateMgr; 152 153 /// SymMgr - Object that manages the symbol information. 154 SymbolManager &SymMgr; 155 156 /// MRMgr - MemRegionManager object that creates memory regions. 157 MemRegionManager &MRMgr; 158 159 /// svalBuilder - SValBuilder object that creates SVals from expressions. 160 SValBuilder &svalBuilder; 161 162 unsigned int currStmtIdx = 0; 163 const NodeBuilderContext *currBldrCtx = nullptr; 164 165 /// Helper object to determine if an Objective-C message expression 166 /// implicitly never returns. 167 ObjCNoReturn ObjCNoRet; 168 169 /// The BugReporter associated with this engine. It is important that 170 /// this object be placed at the very end of member variables so that its 171 /// destructor is called before the rest of the ExprEngine is destroyed. 172 PathSensitiveBugReporter BR; 173 174 /// The functions which have been analyzed through inlining. This is owned by 175 /// AnalysisConsumer. It can be null. 176 SetOfConstDecls *VisitedCallees; 177 178 /// The flag, which specifies the mode of inlining for the engine. 179 InliningModes HowToInline; 180 181 public: 182 ExprEngine(cross_tu::CrossTranslationUnitContext &CTU, AnalysisManager &mgr, 183 SetOfConstDecls *VisitedCalleesIn, 184 FunctionSummariesTy *FS, InliningModes HowToInlineIn); 185 186 virtual ~ExprEngine() = default; 187 188 /// Returns true if there is still simulation state on the worklist. 189 bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) { 190 assert(L->inTopFrame()); 191 BR.setAnalysisEntryPoint(L->getDecl()); 192 return Engine.ExecuteWorkList(L, Steps, nullptr); 193 } 194 195 /// getContext - Return the ASTContext associated with this analysis. getContext()196 ASTContext &getContext() const { return AMgr.getASTContext(); } 197 getAnalysisManager()198 AnalysisManager &getAnalysisManager() { return AMgr; } 199 getAnalysisDeclContextManager()200 AnalysisDeclContextManager &getAnalysisDeclContextManager() { 201 return AMgr.getAnalysisDeclContextManager(); 202 } 203 getCheckerManager()204 CheckerManager &getCheckerManager() const { 205 return *AMgr.getCheckerManager(); 206 } 207 getSValBuilder()208 SValBuilder &getSValBuilder() { return svalBuilder; } 209 getBugReporter()210 BugReporter &getBugReporter() { return BR; } 211 212 cross_tu::CrossTranslationUnitContext * getCrossTranslationUnitContext()213 getCrossTranslationUnitContext() { 214 return &CTU; 215 } 216 getBuilderContext()217 const NodeBuilderContext &getBuilderContext() { 218 assert(currBldrCtx); 219 return *currBldrCtx; 220 } 221 222 const Stmt *getStmt() const; 223 getRootLocationContext()224 const LocationContext *getRootLocationContext() const { 225 assert(G.roots_begin() != G.roots_end()); 226 return (*G.roots_begin())->getLocation().getLocationContext(); 227 } 228 getCFGElementRef()229 CFGBlock::ConstCFGElementRef getCFGElementRef() const { 230 const CFGBlock *blockPtr = currBldrCtx ? currBldrCtx->getBlock() : nullptr; 231 return {blockPtr, currStmtIdx}; 232 } 233 234 /// Dump graph to the specified filename. 235 /// If filename is empty, generate a temporary one. 236 /// \return The filename the graph is written into. 237 std::string DumpGraph(bool trim = false, StringRef Filename=""); 238 239 /// Dump the graph consisting of the given nodes to a specified filename. 240 /// Generate a temporary filename if it's not provided. 241 /// \return The filename the graph is written into. 242 std::string DumpGraph(ArrayRef<const ExplodedNode *> Nodes, 243 StringRef Filename = ""); 244 245 /// Visualize the ExplodedGraph created by executing the simulation. 246 void ViewGraph(bool trim = false); 247 248 /// Visualize a trimmed ExplodedGraph that only contains paths to the given 249 /// nodes. 250 void ViewGraph(ArrayRef<const ExplodedNode *> Nodes); 251 252 /// getInitialState - Return the initial state used for the root vertex 253 /// in the ExplodedGraph. 254 ProgramStateRef getInitialState(const LocationContext *InitLoc); 255 getGraph()256 ExplodedGraph &getGraph() { return G; } getGraph()257 const ExplodedGraph &getGraph() const { return G; } 258 259 /// Run the analyzer's garbage collection - remove dead symbols and 260 /// bindings from the state. 261 /// 262 /// Checkers can participate in this process with two callbacks: 263 /// \c checkLiveSymbols and \c checkDeadSymbols. See the CheckerDocumentation 264 /// class for more information. 265 /// 266 /// \param Node The predecessor node, from which the processing should start. 267 /// \param Out The returned set of output nodes. 268 /// \param ReferenceStmt The statement which is about to be processed. 269 /// Everything needed for this statement should be considered live. 270 /// A null statement means that everything in child LocationContexts 271 /// is dead. 272 /// \param LC The location context of the \p ReferenceStmt. A null location 273 /// context means that we have reached the end of analysis and that 274 /// all statements and local variables should be considered dead. 275 /// \param DiagnosticStmt Used as a location for any warnings that should 276 /// occur while removing the dead (e.g. leaks). By default, the 277 /// \p ReferenceStmt is used. 278 /// \param K Denotes whether this is a pre- or post-statement purge. This 279 /// must only be ProgramPoint::PostStmtPurgeDeadSymbolsKind if an 280 /// entire location context is being cleared, in which case the 281 /// \p ReferenceStmt must either be a ReturnStmt or \c NULL. Otherwise, 282 /// it must be ProgramPoint::PreStmtPurgeDeadSymbolsKind (the default) 283 /// and \p ReferenceStmt must be valid (non-null). 284 void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out, 285 const Stmt *ReferenceStmt, const LocationContext *LC, 286 const Stmt *DiagnosticStmt = nullptr, 287 ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind); 288 289 /// processCFGElement - Called by CoreEngine. Used to generate new successor 290 /// nodes by processing the 'effects' of a CFG element. 291 void processCFGElement(const CFGElement E, ExplodedNode *Pred, 292 unsigned StmtIdx, NodeBuilderContext *Ctx); 293 294 void ProcessStmt(const Stmt *S, ExplodedNode *Pred); 295 296 void ProcessLoopExit(const Stmt* S, ExplodedNode *Pred); 297 298 void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred); 299 300 void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred); 301 302 void ProcessNewAllocator(const CXXNewExpr *NE, ExplodedNode *Pred); 303 304 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 305 ExplodedNode *Pred, ExplodedNodeSet &Dst); 306 void ProcessDeleteDtor(const CFGDeleteDtor D, 307 ExplodedNode *Pred, ExplodedNodeSet &Dst); 308 void ProcessBaseDtor(const CFGBaseDtor D, 309 ExplodedNode *Pred, ExplodedNodeSet &Dst); 310 void ProcessMemberDtor(const CFGMemberDtor D, 311 ExplodedNode *Pred, ExplodedNodeSet &Dst); 312 void ProcessTemporaryDtor(const CFGTemporaryDtor D, 313 ExplodedNode *Pred, ExplodedNodeSet &Dst); 314 315 /// Called by CoreEngine when processing the entrance of a CFGBlock. 316 void processCFGBlockEntrance(const BlockEdge &L, 317 NodeBuilderWithSinks &nodeBuilder, 318 ExplodedNode *Pred); 319 320 /// ProcessBranch - Called by CoreEngine. Used to generate successor 321 /// nodes by processing the 'effects' of a branch condition. 322 void processBranch(const Stmt *Condition, 323 NodeBuilderContext& BuilderCtx, 324 ExplodedNode *Pred, 325 ExplodedNodeSet &Dst, 326 const CFGBlock *DstT, 327 const CFGBlock *DstF); 328 329 /// Called by CoreEngine. 330 /// Used to generate successor nodes for temporary destructors depending 331 /// on whether the corresponding constructor was visited. 332 void processCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE, 333 NodeBuilderContext &BldCtx, 334 ExplodedNode *Pred, ExplodedNodeSet &Dst, 335 const CFGBlock *DstT, 336 const CFGBlock *DstF); 337 338 /// Called by CoreEngine. Used to processing branching behavior 339 /// at static initializers. 340 void processStaticInitializer(const DeclStmt *DS, 341 NodeBuilderContext& BuilderCtx, 342 ExplodedNode *Pred, 343 ExplodedNodeSet &Dst, 344 const CFGBlock *DstT, 345 const CFGBlock *DstF); 346 347 /// processIndirectGoto - Called by CoreEngine. Used to generate successor 348 /// nodes by processing the 'effects' of a computed goto jump. 349 void processIndirectGoto(IndirectGotoNodeBuilder& builder); 350 351 /// ProcessSwitch - Called by CoreEngine. Used to generate successor 352 /// nodes by processing the 'effects' of a switch statement. 353 void processSwitch(SwitchNodeBuilder& builder); 354 355 /// Called by CoreEngine. Used to notify checkers that processing a 356 /// function has begun. Called for both inlined and top-level functions. 357 void processBeginOfFunction(NodeBuilderContext &BC, 358 ExplodedNode *Pred, ExplodedNodeSet &Dst, 359 const BlockEdge &L); 360 361 /// Called by CoreEngine. Used to notify checkers that processing a 362 /// function has ended. Called for both inlined and top-level functions. 363 void processEndOfFunction(NodeBuilderContext& BC, 364 ExplodedNode *Pred, 365 const ReturnStmt *RS = nullptr); 366 367 /// Remove dead bindings/symbols before exiting a function. 368 void removeDeadOnEndOfFunction(NodeBuilderContext& BC, 369 ExplodedNode *Pred, 370 ExplodedNodeSet &Dst); 371 372 /// Generate the entry node of the callee. 373 void processCallEnter(NodeBuilderContext& BC, CallEnter CE, 374 ExplodedNode *Pred); 375 376 /// Generate the sequence of nodes that simulate the call exit and the post 377 /// visit for CallExpr. 378 void processCallExit(ExplodedNode *Pred); 379 380 /// Called by CoreEngine when the analysis worklist has terminated. 381 void processEndWorklist(); 382 383 /// evalAssume - Callback function invoked by the ConstraintManager when 384 /// making assumptions about state values. 385 ProgramStateRef processAssume(ProgramStateRef state, SVal cond, 386 bool assumption); 387 388 /// processRegionChanges - Called by ProgramStateManager whenever a change is made 389 /// to the store. Used to update checkers that track region values. 390 ProgramStateRef 391 processRegionChanges(ProgramStateRef state, 392 const InvalidatedSymbols *invalidated, 393 ArrayRef<const MemRegion *> ExplicitRegions, 394 ArrayRef<const MemRegion *> Regions, 395 const LocationContext *LCtx, 396 const CallEvent *Call); 397 398 inline ProgramStateRef processRegionChange(ProgramStateRef state,const MemRegion * MR,const LocationContext * LCtx)399 processRegionChange(ProgramStateRef state, 400 const MemRegion* MR, 401 const LocationContext *LCtx) { 402 return processRegionChanges(state, nullptr, MR, MR, LCtx, nullptr); 403 } 404 405 /// printJson - Called by ProgramStateManager to print checker-specific data. 406 void printJson(raw_ostream &Out, ProgramStateRef State, 407 const LocationContext *LCtx, const char *NL, 408 unsigned int Space, bool IsDot) const; 409 getStateManager()410 ProgramStateManager &getStateManager() { return StateMgr; } 411 getStoreManager()412 StoreManager &getStoreManager() { return StateMgr.getStoreManager(); } 413 getConstraintManager()414 ConstraintManager &getConstraintManager() { 415 return StateMgr.getConstraintManager(); 416 } 417 418 // FIXME: Remove when we migrate over to just using SValBuilder. getBasicVals()419 BasicValueFactory &getBasicVals() { 420 return StateMgr.getBasicVals(); 421 } 422 getSymbolManager()423 SymbolManager &getSymbolManager() { return SymMgr; } getRegionManager()424 MemRegionManager &getRegionManager() { return MRMgr; } 425 getDataTags()426 DataTag::Factory &getDataTags() { return Engine.getDataTags(); } 427 428 // Functions for external checking of whether we have unfinished work wasBlocksExhausted()429 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); } hasEmptyWorkList()430 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); } hasWorkRemaining()431 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); } 432 getCoreEngine()433 const CoreEngine &getCoreEngine() const { return Engine; } 434 435 public: 436 /// Visit - Transfer function logic for all statements. Dispatches to 437 /// other functions that handle specific kinds of statements. 438 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst); 439 440 /// VisitArrayInitLoopExpr - Transfer function for array init loop. 441 void VisitArrayInitLoopExpr(const ArrayInitLoopExpr *Ex, ExplodedNode *Pred, 442 ExplodedNodeSet &Dst); 443 444 /// VisitArraySubscriptExpr - Transfer function for array accesses. 445 void VisitArraySubscriptExpr(const ArraySubscriptExpr *Ex, 446 ExplodedNode *Pred, 447 ExplodedNodeSet &Dst); 448 449 /// VisitGCCAsmStmt - Transfer function logic for inline asm. 450 void VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred, 451 ExplodedNodeSet &Dst); 452 453 /// VisitMSAsmStmt - Transfer function logic for MS inline asm. 454 void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred, 455 ExplodedNodeSet &Dst); 456 457 /// VisitBlockExpr - Transfer function logic for BlockExprs. 458 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 459 ExplodedNodeSet &Dst); 460 461 /// VisitLambdaExpr - Transfer function logic for LambdaExprs. 462 void VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred, 463 ExplodedNodeSet &Dst); 464 465 /// VisitBinaryOperator - Transfer function logic for binary operators. 466 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred, 467 ExplodedNodeSet &Dst); 468 469 470 /// VisitCall - Transfer function for function calls. 471 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 472 ExplodedNodeSet &Dst); 473 474 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 475 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 476 ExplodedNodeSet &Dst); 477 478 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 479 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 480 ExplodedNode *Pred, ExplodedNodeSet &Dst); 481 482 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 483 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D, 484 ExplodedNode *Pred, ExplodedNodeSet &Dst); 485 486 /// VisitDeclStmt - Transfer function logic for DeclStmts. 487 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 488 ExplodedNodeSet &Dst); 489 490 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 491 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R, 492 ExplodedNode *Pred, ExplodedNodeSet &Dst); 493 494 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred, 495 ExplodedNodeSet &Dst); 496 497 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 498 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 499 ExplodedNodeSet &Dst); 500 501 /// VisitMemberExpr - Transfer function for member expressions. 502 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred, 503 ExplodedNodeSet &Dst); 504 505 /// VisitAtomicExpr - Transfer function for builtin atomic expressions 506 void VisitAtomicExpr(const AtomicExpr *E, ExplodedNode *Pred, 507 ExplodedNodeSet &Dst); 508 509 /// Transfer function logic for ObjCAtSynchronizedStmts. 510 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 511 ExplodedNode *Pred, ExplodedNodeSet &Dst); 512 513 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 514 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred, 515 ExplodedNodeSet &Dst); 516 517 /// VisitObjCForCollectionStmt - Transfer function logic for 518 /// ObjCForCollectionStmt. 519 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S, 520 ExplodedNode *Pred, ExplodedNodeSet &Dst); 521 522 void VisitObjCMessage(const ObjCMessageExpr *ME, ExplodedNode *Pred, 523 ExplodedNodeSet &Dst); 524 525 /// VisitReturnStmt - Transfer function logic for return statements. 526 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred, 527 ExplodedNodeSet &Dst); 528 529 /// VisitOffsetOfExpr - Transfer function for offsetof. 530 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred, 531 ExplodedNodeSet &Dst); 532 533 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 534 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 535 ExplodedNode *Pred, ExplodedNodeSet &Dst); 536 537 /// VisitUnaryOperator - Transfer function logic for unary operators. 538 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred, 539 ExplodedNodeSet &Dst); 540 541 /// Handle ++ and -- (both pre- and post-increment). 542 void VisitIncrementDecrementOperator(const UnaryOperator* U, 543 ExplodedNode *Pred, 544 ExplodedNodeSet &Dst); 545 546 void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE, 547 ExplodedNodeSet &PreVisit, 548 ExplodedNodeSet &Dst); 549 550 void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred, 551 ExplodedNodeSet &Dst); 552 553 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 554 ExplodedNodeSet & Dst); 555 556 void VisitCXXConstructExpr(const CXXConstructExpr *E, ExplodedNode *Pred, 557 ExplodedNodeSet &Dst); 558 559 void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E, 560 ExplodedNode *Pred, ExplodedNodeSet &Dst); 561 562 void VisitCXXDestructor(QualType ObjectType, const MemRegion *Dest, 563 const Stmt *S, bool IsBaseDtor, 564 ExplodedNode *Pred, ExplodedNodeSet &Dst, 565 EvalCallOptions &Options); 566 567 void VisitCXXNewAllocatorCall(const CXXNewExpr *CNE, 568 ExplodedNode *Pred, 569 ExplodedNodeSet &Dst); 570 571 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 572 ExplodedNodeSet &Dst); 573 574 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 575 ExplodedNodeSet &Dst); 576 577 /// Create a C++ temporary object for an rvalue. 578 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 579 ExplodedNode *Pred, 580 ExplodedNodeSet &Dst); 581 582 /// evalEagerlyAssumeBinOpBifurcation - Given the nodes in 'Src', eagerly assume symbolic 583 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 584 /// with those assumptions. 585 void evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 586 const Expr *Ex); 587 588 static std::pair<const ProgramPointTag *, const ProgramPointTag *> 589 geteagerlyAssumeBinOpBifurcationTags(); 590 591 ProgramStateRef handleLValueBitCast(ProgramStateRef state, const Expr *Ex, 592 const LocationContext *LCtx, QualType T, 593 QualType ExTy, const CastExpr *CastE, 594 StmtNodeBuilder &Bldr, 595 ExplodedNode *Pred); 596 597 void handleUOExtension(ExplodedNode *N, const UnaryOperator *U, 598 StmtNodeBuilder &Bldr); 599 600 public: evalBinOp(ProgramStateRef ST,BinaryOperator::Opcode Op,SVal LHS,SVal RHS,QualType T)601 SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op, 602 SVal LHS, SVal RHS, QualType T) { 603 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 604 } 605 606 /// Retreives which element is being constructed in a non-POD type array. 607 static std::optional<unsigned> 608 getIndexOfElementToConstruct(ProgramStateRef State, const CXXConstructExpr *E, 609 const LocationContext *LCtx); 610 611 /// Retreives which element is being destructed in a non-POD type array. 612 static std::optional<unsigned> 613 getPendingArrayDestruction(ProgramStateRef State, 614 const LocationContext *LCtx); 615 616 /// Retreives the size of the array in the pending ArrayInitLoopExpr. 617 static std::optional<unsigned> 618 getPendingInitLoop(ProgramStateRef State, const CXXConstructExpr *E, 619 const LocationContext *LCtx); 620 621 /// By looking at a certain item that may be potentially part of an object's 622 /// ConstructionContext, retrieve such object's location. A particular 623 /// statement can be transparently passed as \p Item in most cases. 624 static std::optional<SVal> 625 getObjectUnderConstruction(ProgramStateRef State, 626 const ConstructionContextItem &Item, 627 const LocationContext *LC); 628 629 /// Call PointerEscape callback when a value escapes as a result of bind. 630 ProgramStateRef processPointerEscapedOnBind( 631 ProgramStateRef State, ArrayRef<std::pair<SVal, SVal>> LocAndVals, 632 const LocationContext *LCtx, PointerEscapeKind Kind, 633 const CallEvent *Call); 634 635 /// Call PointerEscape callback when a value escapes as a result of 636 /// region invalidation. 637 /// \param[in] ITraits Specifies invalidation traits for regions/symbols. 638 ProgramStateRef notifyCheckersOfPointerEscape( 639 ProgramStateRef State, 640 const InvalidatedSymbols *Invalidated, 641 ArrayRef<const MemRegion *> ExplicitRegions, 642 const CallEvent *Call, 643 RegionAndSymbolInvalidationTraits &ITraits); 644 645 private: 646 /// evalBind - Handle the semantics of binding a value to a specific location. 647 /// This method is used by evalStore, VisitDeclStmt, and others. 648 void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred, 649 SVal location, SVal Val, bool atDeclInit = false, 650 const ProgramPoint *PP = nullptr); 651 652 ProgramStateRef 653 processPointerEscapedOnBind(ProgramStateRef State, 654 SVal Loc, SVal Val, 655 const LocationContext *LCtx); 656 657 /// A simple wrapper when you only need to notify checkers of pointer-escape 658 /// of some values. 659 ProgramStateRef escapeValues(ProgramStateRef State, ArrayRef<SVal> Vs, 660 PointerEscapeKind K, 661 const CallEvent *Call = nullptr) const; 662 663 public: 664 // FIXME: 'tag' should be removed, and a LocationContext should be used 665 // instead. 666 // FIXME: Comment on the meaning of the arguments, when 'St' may not 667 // be the same as Pred->state, and when 'location' may not be the 668 // same as state->getLValue(Ex). 669 /// Simulate a read of the result of Ex. 670 void evalLoad(ExplodedNodeSet &Dst, 671 const Expr *NodeEx, /* Eventually will be a CFGStmt */ 672 const Expr *BoundExpr, 673 ExplodedNode *Pred, 674 ProgramStateRef St, 675 SVal location, 676 const ProgramPointTag *tag = nullptr, 677 QualType LoadTy = QualType()); 678 679 // FIXME: 'tag' should be removed, and a LocationContext should be used 680 // instead. 681 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE, 682 ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val, 683 const ProgramPointTag *tag = nullptr); 684 685 /// Return the CFG element corresponding to the worklist element 686 /// that is currently being processed by ExprEngine. getCurrentCFGElement()687 CFGElement getCurrentCFGElement() { 688 return (*currBldrCtx->getBlock())[currStmtIdx]; 689 } 690 691 /// Create a new state in which the call return value is binded to the 692 /// call origin expression. 693 ProgramStateRef bindReturnValue(const CallEvent &Call, 694 const LocationContext *LCtx, 695 ProgramStateRef State); 696 697 /// Evaluate a call, running pre- and post-call checkers and allowing checkers 698 /// to be responsible for handling the evaluation of the call itself. 699 void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred, 700 const CallEvent &Call); 701 702 /// Default implementation of call evaluation. 703 void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred, 704 const CallEvent &Call, 705 const EvalCallOptions &CallOpts = {}); 706 707 /// Find location of the object that is being constructed by a given 708 /// constructor. This should ideally always succeed but due to not being 709 /// fully implemented it sometimes indicates that it failed via its 710 /// out-parameter CallOpts; in such cases a fake temporary region is 711 /// returned, which is better than nothing but does not represent 712 /// the actual behavior of the program. The Idx parameter is used if we 713 /// construct an array of objects. In that case it points to the index 714 /// of the continuous memory region. 715 /// E.g.: 716 /// For `int arr[4]` this index can be 0,1,2,3. 717 /// For `int arr2[3][3]` this index can be 0,1,...,7,8. 718 /// A multi-dimensional array is also a continuous memory location in a 719 /// row major order, so for arr[0][0] Idx is 0 and for arr[2][2] Idx is 8. 720 SVal computeObjectUnderConstruction(const Expr *E, ProgramStateRef State, 721 const NodeBuilderContext *BldrCtx, 722 const LocationContext *LCtx, 723 const ConstructionContext *CC, 724 EvalCallOptions &CallOpts, 725 unsigned Idx = 0); 726 727 /// Update the program state with all the path-sensitive information 728 /// that's necessary to perform construction of an object with a given 729 /// syntactic construction context. V and CallOpts have to be obtained from 730 /// computeObjectUnderConstruction() invoked with the same set of 731 /// the remaining arguments (E, State, LCtx, CC). 732 ProgramStateRef updateObjectsUnderConstruction( 733 SVal V, const Expr *E, ProgramStateRef State, const LocationContext *LCtx, 734 const ConstructionContext *CC, const EvalCallOptions &CallOpts); 735 736 /// A convenient wrapper around computeObjectUnderConstruction 737 /// and updateObjectsUnderConstruction. 738 std::pair<ProgramStateRef, SVal> handleConstructionContext( 739 const Expr *E, ProgramStateRef State, const NodeBuilderContext *BldrCtx, 740 const LocationContext *LCtx, const ConstructionContext *CC, 741 EvalCallOptions &CallOpts, unsigned Idx = 0) { 742 743 SVal V = computeObjectUnderConstruction(E, State, BldrCtx, LCtx, CC, 744 CallOpts, Idx); 745 State = updateObjectsUnderConstruction(V, E, State, LCtx, CC, CallOpts); 746 747 return std::make_pair(State, V); 748 } 749 750 private: 751 ProgramStateRef finishArgumentConstruction(ProgramStateRef State, 752 const CallEvent &Call); 753 void finishArgumentConstruction(ExplodedNodeSet &Dst, ExplodedNode *Pred, 754 const CallEvent &Call); 755 756 void evalLocation(ExplodedNodeSet &Dst, 757 const Stmt *NodeEx, /* This will eventually be a CFGStmt */ 758 const Stmt *BoundEx, 759 ExplodedNode *Pred, 760 ProgramStateRef St, 761 SVal location, 762 bool isLoad); 763 764 /// Count the stack depth and determine if the call is recursive. 765 void examineStackFrames(const Decl *D, const LocationContext *LCtx, 766 bool &IsRecursive, unsigned &StackDepth); 767 768 enum CallInlinePolicy { 769 CIP_Allowed, 770 CIP_DisallowedOnce, 771 CIP_DisallowedAlways 772 }; 773 774 /// See if a particular call should be inlined, by only looking 775 /// at the call event and the current state of analysis. 776 CallInlinePolicy mayInlineCallKind(const CallEvent &Call, 777 const ExplodedNode *Pred, 778 AnalyzerOptions &Opts, 779 const EvalCallOptions &CallOpts); 780 781 /// See if the given AnalysisDeclContext is built for a function that we 782 /// should always inline simply because it's small enough. 783 /// Apart from "small" functions, we also have "large" functions 784 /// (cf. isLarge()), some of which are huge (cf. isHuge()), and we classify 785 /// the remaining functions as "medium". 786 bool isSmall(AnalysisDeclContext *ADC) const; 787 788 /// See if the given AnalysisDeclContext is built for a function that we 789 /// should inline carefully because it looks pretty large. 790 bool isLarge(AnalysisDeclContext *ADC) const; 791 792 /// See if the given AnalysisDeclContext is built for a function that we 793 /// should never inline because it's legit gigantic. 794 bool isHuge(AnalysisDeclContext *ADC) const; 795 796 /// See if the given AnalysisDeclContext is built for a function that we 797 /// should inline, just by looking at the declaration of the function. 798 bool mayInlineDecl(AnalysisDeclContext *ADC) const; 799 800 /// Checks our policies and decides weither the given call should be inlined. 801 bool shouldInlineCall(const CallEvent &Call, const Decl *D, 802 const ExplodedNode *Pred, 803 const EvalCallOptions &CallOpts = {}); 804 805 /// Checks whether our policies allow us to inline a non-POD type array 806 /// construction. 807 bool shouldInlineArrayConstruction(const ProgramStateRef State, 808 const CXXConstructExpr *CE, 809 const LocationContext *LCtx); 810 811 /// Checks whether our policies allow us to inline a non-POD type array 812 /// destruction. 813 /// \param Size The size of the array. 814 bool shouldInlineArrayDestruction(uint64_t Size); 815 816 /// Prepares the program state for array destruction. If no error happens 817 /// the function binds a 'PendingArrayDestruction' entry to the state, which 818 /// it returns along with the index. If any error happens (we fail to read 819 /// the size, the index would be -1, etc.) the function will return the 820 /// original state along with an index of 0. The actual element count of the 821 /// array can be accessed by the optional 'ElementCountVal' parameter. \param 822 /// State The program state. \param Region The memory region where the array 823 /// is stored. \param ElementTy The type an element in the array. \param LCty 824 /// The location context. \param ElementCountVal A pointer to an optional 825 /// SVal. If specified, the size of the array will be returned in it. It can 826 /// be Unknown. 827 std::pair<ProgramStateRef, uint64_t> prepareStateForArrayDestruction( 828 const ProgramStateRef State, const MemRegion *Region, 829 const QualType &ElementTy, const LocationContext *LCtx, 830 SVal *ElementCountVal = nullptr); 831 832 /// Checks whether we construct an array of non-POD type, and decides if the 833 /// constructor should be inkoved once again. 834 bool shouldRepeatCtorCall(ProgramStateRef State, const CXXConstructExpr *E, 835 const LocationContext *LCtx); 836 837 void inlineCall(WorkList *WList, const CallEvent &Call, const Decl *D, 838 NodeBuilder &Bldr, ExplodedNode *Pred, ProgramStateRef State); 839 840 void ctuBifurcate(const CallEvent &Call, const Decl *D, NodeBuilder &Bldr, 841 ExplodedNode *Pred, ProgramStateRef State); 842 843 /// Returns true if the CTU analysis is running its second phase. isSecondPhaseCTU()844 bool isSecondPhaseCTU() { return IsCTUEnabled && !Engine.getCTUWorkList(); } 845 846 /// Conservatively evaluate call by invalidating regions and binding 847 /// a conjured return value. 848 void conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr, 849 ExplodedNode *Pred, ProgramStateRef State); 850 851 /// Either inline or process the call conservatively (or both), based 852 /// on DynamicDispatchBifurcation data. 853 void BifurcateCall(const MemRegion *BifurReg, 854 const CallEvent &Call, const Decl *D, NodeBuilder &Bldr, 855 ExplodedNode *Pred); 856 857 bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC); 858 859 /// Models a trivial copy or move constructor or trivial assignment operator 860 /// call with a simple bind. 861 void performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred, 862 const CallEvent &Call); 863 864 /// If the value of the given expression \p InitWithAdjustments is a NonLoc, 865 /// copy it into a new temporary object region, and replace the value of the 866 /// expression with that. 867 /// 868 /// If \p Result is provided, the new region will be bound to this expression 869 /// instead of \p InitWithAdjustments. 870 /// 871 /// Returns the temporary region with adjustments into the optional 872 /// OutRegionWithAdjustments out-parameter if a new region was indeed needed, 873 /// otherwise sets it to nullptr. 874 ProgramStateRef createTemporaryRegionIfNeeded( 875 ProgramStateRef State, const LocationContext *LC, 876 const Expr *InitWithAdjustments, const Expr *Result = nullptr, 877 const SubRegion **OutRegionWithAdjustments = nullptr); 878 879 /// Returns a region representing the `Idx`th element of a (possibly 880 /// multi-dimensional) array, for the purposes of element construction or 881 /// destruction. 882 /// 883 /// On return, \p Ty will be set to the base type of the array. 884 /// 885 /// If the type is not an array type at all, the original value is returned. 886 /// Otherwise the "IsArray" flag is set. 887 static SVal makeElementRegion(ProgramStateRef State, SVal LValue, 888 QualType &Ty, bool &IsArray, unsigned Idx = 0); 889 890 /// Common code that handles either a CXXConstructExpr or a 891 /// CXXInheritedCtorInitExpr. 892 void handleConstructor(const Expr *E, ExplodedNode *Pred, 893 ExplodedNodeSet &Dst); 894 895 public: 896 /// Note whether this loop has any more iteratios to model. These methods are 897 /// essentially an interface for a GDM trait. Further reading in 898 /// ExprEngine::VisitObjCForCollectionStmt(). 899 [[nodiscard]] static ProgramStateRef 900 setWhetherHasMoreIteration(ProgramStateRef State, 901 const ObjCForCollectionStmt *O, 902 const LocationContext *LC, bool HasMoreIteraton); 903 904 [[nodiscard]] static ProgramStateRef 905 removeIterationState(ProgramStateRef State, const ObjCForCollectionStmt *O, 906 const LocationContext *LC); 907 908 [[nodiscard]] static bool hasMoreIteration(ProgramStateRef State, 909 const ObjCForCollectionStmt *O, 910 const LocationContext *LC); 911 912 private: 913 /// Assuming we construct an array of non-POD types, this method allows us 914 /// to store which element is to be constructed next. 915 static ProgramStateRef 916 setIndexOfElementToConstruct(ProgramStateRef State, const CXXConstructExpr *E, 917 const LocationContext *LCtx, unsigned Idx); 918 919 static ProgramStateRef 920 removeIndexOfElementToConstruct(ProgramStateRef State, 921 const CXXConstructExpr *E, 922 const LocationContext *LCtx); 923 924 /// Assuming we destruct an array of non-POD types, this method allows us 925 /// to store which element is to be destructed next. 926 static ProgramStateRef setPendingArrayDestruction(ProgramStateRef State, 927 const LocationContext *LCtx, 928 unsigned Idx); 929 930 static ProgramStateRef 931 removePendingArrayDestruction(ProgramStateRef State, 932 const LocationContext *LCtx); 933 934 /// Sets the size of the array in a pending ArrayInitLoopExpr. 935 static ProgramStateRef setPendingInitLoop(ProgramStateRef State, 936 const CXXConstructExpr *E, 937 const LocationContext *LCtx, 938 unsigned Idx); 939 940 static ProgramStateRef removePendingInitLoop(ProgramStateRef State, 941 const CXXConstructExpr *E, 942 const LocationContext *LCtx); 943 944 static ProgramStateRef 945 removeStateTraitsUsedForArrayEvaluation(ProgramStateRef State, 946 const CXXConstructExpr *E, 947 const LocationContext *LCtx); 948 949 /// Store the location of a C++ object corresponding to a statement 950 /// until the statement is actually encountered. For example, if a DeclStmt 951 /// has CXXConstructExpr as its initializer, the object would be considered 952 /// to be "under construction" between CXXConstructExpr and DeclStmt. 953 /// This allows, among other things, to keep bindings to variable's fields 954 /// made within the constructor alive until its declaration actually 955 /// goes into scope. 956 static ProgramStateRef 957 addObjectUnderConstruction(ProgramStateRef State, 958 const ConstructionContextItem &Item, 959 const LocationContext *LC, SVal V); 960 961 /// Mark the object sa fully constructed, cleaning up the state trait 962 /// that tracks objects under construction. 963 static ProgramStateRef 964 finishObjectConstruction(ProgramStateRef State, 965 const ConstructionContextItem &Item, 966 const LocationContext *LC); 967 968 /// If the given expression corresponds to a temporary that was used for 969 /// passing into an elidable copy/move constructor and that constructor 970 /// was actually elided, track that we also need to elide the destructor. 971 static ProgramStateRef elideDestructor(ProgramStateRef State, 972 const CXXBindTemporaryExpr *BTE, 973 const LocationContext *LC); 974 975 /// Stop tracking the destructor that corresponds to an elided constructor. 976 static ProgramStateRef 977 cleanupElidedDestructor(ProgramStateRef State, 978 const CXXBindTemporaryExpr *BTE, 979 const LocationContext *LC); 980 981 /// Returns true if the given expression corresponds to a temporary that 982 /// was constructed for passing into an elidable copy/move constructor 983 /// and that constructor was actually elided. 984 static bool isDestructorElided(ProgramStateRef State, 985 const CXXBindTemporaryExpr *BTE, 986 const LocationContext *LC); 987 988 /// Check if all objects under construction have been fully constructed 989 /// for the given context range (including FromLC, not including ToLC). 990 /// This is useful for assertions. Also checks if elided destructors 991 /// were cleaned up. 992 static bool areAllObjectsFullyConstructed(ProgramStateRef State, 993 const LocationContext *FromLC, 994 const LocationContext *ToLC); 995 }; 996 997 /// Traits for storing the call processing policy inside GDM. 998 /// The GDM stores the corresponding CallExpr pointer. 999 // FIXME: This does not use the nice trait macros because it must be accessible 1000 // from multiple translation units. 1001 struct ReplayWithoutInlining{}; 1002 template <> 1003 struct ProgramStateTrait<ReplayWithoutInlining> : 1004 public ProgramStatePartialTrait<const void*> { 1005 static void *GDMIndex(); 1006 }; 1007 1008 } // namespace ento 1009 1010 } // namespace clang 1011 1012 #endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H 1013