ExprEngine.h revision 360784
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/BugReporter/BugReporter.h" 25#include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h" 26#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" 27#include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h" 28#include "clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h" 29#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 30#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 31#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h" 32#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h" 33#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h" 34#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h" 35#include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h" 36#include "llvm/ADT/ArrayRef.h" 37#include <cassert> 38#include <utility> 39 40namespace clang { 41 42class AnalysisDeclContextManager; 43class AnalyzerOptions; 44class ASTContext; 45class ConstructionContext; 46class CXXBindTemporaryExpr; 47class CXXCatchStmt; 48class CXXConstructExpr; 49class CXXDeleteExpr; 50class CXXNewExpr; 51class CXXThisExpr; 52class Decl; 53class DeclStmt; 54class GCCAsmStmt; 55class LambdaExpr; 56class LocationContext; 57class MaterializeTemporaryExpr; 58class MSAsmStmt; 59class NamedDecl; 60class ObjCAtSynchronizedStmt; 61class ObjCForCollectionStmt; 62class ObjCIvarRefExpr; 63class ObjCMessageExpr; 64class ReturnStmt; 65class Stmt; 66 67namespace cross_tu { 68 69class CrossTranslationUnitContext; 70 71} // namespace cross_tu 72 73namespace ento { 74 75class BasicValueFactory; 76class CallEvent; 77class CheckerManager; 78class ConstraintManager; 79class CXXTempObjectRegion; 80class MemRegion; 81class RegionAndSymbolInvalidationTraits; 82class SymbolManager; 83 84class ExprEngine : public SubEngine { 85public: 86 /// The modes of inlining, which override the default analysis-wide settings. 87 enum InliningModes { 88 /// Follow the default settings for inlining callees. 89 Inline_Regular = 0, 90 91 /// Do minimal inlining of callees. 92 Inline_Minimal = 0x1 93 }; 94 95 /// Hints for figuring out of a call should be inlined during evalCall(). 96 struct EvalCallOptions { 97 /// This call is a constructor or a destructor for which we do not currently 98 /// compute the this-region correctly. 99 bool IsCtorOrDtorWithImproperlyModeledTargetRegion = false; 100 101 /// This call is a constructor or a destructor for a single element within 102 /// an array, a part of array construction or destruction. 103 bool IsArrayCtorOrDtor = false; 104 105 /// This call is a constructor or a destructor of a temporary value. 106 bool IsTemporaryCtorOrDtor = false; 107 108 /// This call is a constructor for a temporary that is lifetime-extended 109 /// by binding it to a reference-type field within an aggregate, 110 /// for example 'A { const C &c; }; A a = { C() };' 111 bool IsTemporaryLifetimeExtendedViaAggregate = false; 112 113 EvalCallOptions() {} 114 }; 115 116private: 117 cross_tu::CrossTranslationUnitContext &CTU; 118 119 AnalysisManager &AMgr; 120 121 AnalysisDeclContextManager &AnalysisDeclContexts; 122 123 CoreEngine Engine; 124 125 /// G - the simulation graph. 126 ExplodedGraph &G; 127 128 /// StateMgr - Object that manages the data for all created states. 129 ProgramStateManager StateMgr; 130 131 /// SymMgr - Object that manages the symbol information. 132 SymbolManager &SymMgr; 133 134 /// MRMgr - MemRegionManager object that creates memory regions. 135 MemRegionManager &MRMgr; 136 137 /// svalBuilder - SValBuilder object that creates SVals from expressions. 138 SValBuilder &svalBuilder; 139 140 unsigned int currStmtIdx = 0; 141 const NodeBuilderContext *currBldrCtx = nullptr; 142 143 /// Helper object to determine if an Objective-C message expression 144 /// implicitly never returns. 145 ObjCNoReturn ObjCNoRet; 146 147 /// The BugReporter associated with this engine. It is important that 148 /// this object be placed at the very end of member variables so that its 149 /// destructor is called before the rest of the ExprEngine is destroyed. 150 PathSensitiveBugReporter BR; 151 152 /// The functions which have been analyzed through inlining. This is owned by 153 /// AnalysisConsumer. It can be null. 154 SetOfConstDecls *VisitedCallees; 155 156 /// The flag, which specifies the mode of inlining for the engine. 157 InliningModes HowToInline; 158 159public: 160 ExprEngine(cross_tu::CrossTranslationUnitContext &CTU, AnalysisManager &mgr, 161 SetOfConstDecls *VisitedCalleesIn, 162 FunctionSummariesTy *FS, InliningModes HowToInlineIn); 163 164 ~ExprEngine() override = default; 165 166 /// Returns true if there is still simulation state on the worklist. 167 bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) { 168 return Engine.ExecuteWorkList(L, Steps, nullptr); 169 } 170 171 /// Execute the work list with an initial state. Nodes that reaches the exit 172 /// of the function are added into the Dst set, which represent the exit 173 /// state of the function call. Returns true if there is still simulation 174 /// state on the worklist. 175 bool ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps, 176 ProgramStateRef InitState, 177 ExplodedNodeSet &Dst) { 178 return Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst); 179 } 180 181 /// getContext - Return the ASTContext associated with this analysis. 182 ASTContext &getContext() const { return AMgr.getASTContext(); } 183 184 AnalysisManager &getAnalysisManager() override { return AMgr; } 185 186 AnalysisDeclContextManager &getAnalysisDeclContextManager() { 187 return AMgr.getAnalysisDeclContextManager(); 188 } 189 190 CheckerManager &getCheckerManager() const { 191 return *AMgr.getCheckerManager(); 192 } 193 194 SValBuilder &getSValBuilder() { return svalBuilder; } 195 196 BugReporter &getBugReporter() { return BR; } 197 198 cross_tu::CrossTranslationUnitContext * 199 getCrossTranslationUnitContext() override { 200 return &CTU; 201 } 202 203 const NodeBuilderContext &getBuilderContext() { 204 assert(currBldrCtx); 205 return *currBldrCtx; 206 } 207 208 const Stmt *getStmt() const; 209 210 void GenerateAutoTransition(ExplodedNode *N); 211 void enqueueEndOfPath(ExplodedNodeSet &S); 212 void GenerateCallExitNode(ExplodedNode *N); 213 214 215 /// Dump graph to the specified filename. 216 /// If filename is empty, generate a temporary one. 217 /// \return The filename the graph is written into. 218 std::string DumpGraph(bool trim = false, StringRef Filename=""); 219 220 /// Dump the graph consisting of the given nodes to a specified filename. 221 /// Generate a temporary filename if it's not provided. 222 /// \return The filename the graph is written into. 223 std::string DumpGraph(ArrayRef<const ExplodedNode *> Nodes, 224 StringRef Filename = ""); 225 226 /// Visualize the ExplodedGraph created by executing the simulation. 227 void ViewGraph(bool trim = false); 228 229 /// Visualize a trimmed ExplodedGraph that only contains paths to the given 230 /// nodes. 231 void ViewGraph(ArrayRef<const ExplodedNode *> Nodes); 232 233 /// getInitialState - Return the initial state used for the root vertex 234 /// in the ExplodedGraph. 235 ProgramStateRef getInitialState(const LocationContext *InitLoc) override; 236 237 ExplodedGraph &getGraph() { return G; } 238 const ExplodedGraph &getGraph() const { return G; } 239 240 /// Run the analyzer's garbage collection - remove dead symbols and 241 /// bindings from the state. 242 /// 243 /// Checkers can participate in this process with two callbacks: 244 /// \c checkLiveSymbols and \c checkDeadSymbols. See the CheckerDocumentation 245 /// class for more information. 246 /// 247 /// \param Node The predecessor node, from which the processing should start. 248 /// \param Out The returned set of output nodes. 249 /// \param ReferenceStmt The statement which is about to be processed. 250 /// Everything needed for this statement should be considered live. 251 /// A null statement means that everything in child LocationContexts 252 /// is dead. 253 /// \param LC The location context of the \p ReferenceStmt. A null location 254 /// context means that we have reached the end of analysis and that 255 /// all statements and local variables should be considered dead. 256 /// \param DiagnosticStmt Used as a location for any warnings that should 257 /// occur while removing the dead (e.g. leaks). By default, the 258 /// \p ReferenceStmt is used. 259 /// \param K Denotes whether this is a pre- or post-statement purge. This 260 /// must only be ProgramPoint::PostStmtPurgeDeadSymbolsKind if an 261 /// entire location context is being cleared, in which case the 262 /// \p ReferenceStmt must either be a ReturnStmt or \c NULL. Otherwise, 263 /// it must be ProgramPoint::PreStmtPurgeDeadSymbolsKind (the default) 264 /// and \p ReferenceStmt must be valid (non-null). 265 void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out, 266 const Stmt *ReferenceStmt, const LocationContext *LC, 267 const Stmt *DiagnosticStmt = nullptr, 268 ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind); 269 270 /// processCFGElement - Called by CoreEngine. Used to generate new successor 271 /// nodes by processing the 'effects' of a CFG element. 272 void processCFGElement(const CFGElement E, ExplodedNode *Pred, 273 unsigned StmtIdx, NodeBuilderContext *Ctx) override; 274 275 void ProcessStmt(const Stmt *S, ExplodedNode *Pred); 276 277 void ProcessLoopExit(const Stmt* S, ExplodedNode *Pred); 278 279 void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred); 280 281 void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred); 282 283 void ProcessNewAllocator(const CXXNewExpr *NE, ExplodedNode *Pred); 284 285 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 286 ExplodedNode *Pred, ExplodedNodeSet &Dst); 287 void ProcessDeleteDtor(const CFGDeleteDtor D, 288 ExplodedNode *Pred, ExplodedNodeSet &Dst); 289 void ProcessBaseDtor(const CFGBaseDtor D, 290 ExplodedNode *Pred, ExplodedNodeSet &Dst); 291 void ProcessMemberDtor(const CFGMemberDtor D, 292 ExplodedNode *Pred, ExplodedNodeSet &Dst); 293 void ProcessTemporaryDtor(const CFGTemporaryDtor D, 294 ExplodedNode *Pred, ExplodedNodeSet &Dst); 295 296 /// Called by CoreEngine when processing the entrance of a CFGBlock. 297 void processCFGBlockEntrance(const BlockEdge &L, 298 NodeBuilderWithSinks &nodeBuilder, 299 ExplodedNode *Pred) override; 300 301 /// ProcessBranch - Called by CoreEngine. Used to generate successor 302 /// nodes by processing the 'effects' of a branch condition. 303 void processBranch(const Stmt *Condition, 304 NodeBuilderContext& BuilderCtx, 305 ExplodedNode *Pred, 306 ExplodedNodeSet &Dst, 307 const CFGBlock *DstT, 308 const CFGBlock *DstF) override; 309 310 /// Called by CoreEngine. 311 /// Used to generate successor nodes for temporary destructors depending 312 /// on whether the corresponding constructor was visited. 313 void processCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE, 314 NodeBuilderContext &BldCtx, 315 ExplodedNode *Pred, ExplodedNodeSet &Dst, 316 const CFGBlock *DstT, 317 const CFGBlock *DstF) override; 318 319 /// Called by CoreEngine. Used to processing branching behavior 320 /// at static initializers. 321 void processStaticInitializer(const DeclStmt *DS, 322 NodeBuilderContext& BuilderCtx, 323 ExplodedNode *Pred, 324 ExplodedNodeSet &Dst, 325 const CFGBlock *DstT, 326 const CFGBlock *DstF) override; 327 328 /// processIndirectGoto - Called by CoreEngine. Used to generate successor 329 /// nodes by processing the 'effects' of a computed goto jump. 330 void processIndirectGoto(IndirectGotoNodeBuilder& builder) override; 331 332 /// ProcessSwitch - Called by CoreEngine. Used to generate successor 333 /// nodes by processing the 'effects' of a switch statement. 334 void processSwitch(SwitchNodeBuilder& builder) override; 335 336 /// Called by CoreEngine. Used to notify checkers that processing a 337 /// function has begun. Called for both inlined and and top-level functions. 338 void processBeginOfFunction(NodeBuilderContext &BC, 339 ExplodedNode *Pred, ExplodedNodeSet &Dst, 340 const BlockEdge &L) override; 341 342 /// Called by CoreEngine. Used to notify checkers that processing a 343 /// function has ended. Called for both inlined and and top-level functions. 344 void processEndOfFunction(NodeBuilderContext& BC, 345 ExplodedNode *Pred, 346 const ReturnStmt *RS = nullptr) override; 347 348 /// Remove dead bindings/symbols before exiting a function. 349 void removeDeadOnEndOfFunction(NodeBuilderContext& BC, 350 ExplodedNode *Pred, 351 ExplodedNodeSet &Dst); 352 353 /// Generate the entry node of the callee. 354 void processCallEnter(NodeBuilderContext& BC, CallEnter CE, 355 ExplodedNode *Pred) override; 356 357 /// Generate the sequence of nodes that simulate the call exit and the post 358 /// visit for CallExpr. 359 void processCallExit(ExplodedNode *Pred) override; 360 361 /// Called by CoreEngine when the analysis worklist has terminated. 362 void processEndWorklist() override; 363 364 /// evalAssume - Callback function invoked by the ConstraintManager when 365 /// making assumptions about state values. 366 ProgramStateRef processAssume(ProgramStateRef state, SVal cond, 367 bool assumption) override; 368 369 /// processRegionChanges - Called by ProgramStateManager whenever a change is made 370 /// to the store. Used to update checkers that track region values. 371 ProgramStateRef 372 processRegionChanges(ProgramStateRef state, 373 const InvalidatedSymbols *invalidated, 374 ArrayRef<const MemRegion *> ExplicitRegions, 375 ArrayRef<const MemRegion *> Regions, 376 const LocationContext *LCtx, 377 const CallEvent *Call) override; 378 379 /// printJson - Called by ProgramStateManager to print checker-specific data. 380 void printJson(raw_ostream &Out, ProgramStateRef State, 381 const LocationContext *LCtx, const char *NL, 382 unsigned int Space, bool IsDot) const override; 383 384 ProgramStateManager &getStateManager() override { return StateMgr; } 385 386 StoreManager &getStoreManager() { return StateMgr.getStoreManager(); } 387 388 ConstraintManager &getConstraintManager() { 389 return StateMgr.getConstraintManager(); 390 } 391 392 // FIXME: Remove when we migrate over to just using SValBuilder. 393 BasicValueFactory &getBasicVals() { 394 return StateMgr.getBasicVals(); 395 } 396 397 SymbolManager &getSymbolManager() { return SymMgr; } 398 MemRegionManager &getRegionManager() { return MRMgr; } 399 400 NoteTag::Factory &getNoteTags() { return Engine.getNoteTags(); } 401 402 403 // Functions for external checking of whether we have unfinished work 404 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); } 405 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); } 406 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); } 407 408 const CoreEngine &getCoreEngine() const { return Engine; } 409 410public: 411 /// Visit - Transfer function logic for all statements. Dispatches to 412 /// other functions that handle specific kinds of statements. 413 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst); 414 415 /// VisitArraySubscriptExpr - Transfer function for array accesses. 416 void VisitArraySubscriptExpr(const ArraySubscriptExpr *Ex, 417 ExplodedNode *Pred, 418 ExplodedNodeSet &Dst); 419 420 /// VisitGCCAsmStmt - Transfer function logic for inline asm. 421 void VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred, 422 ExplodedNodeSet &Dst); 423 424 /// VisitMSAsmStmt - Transfer function logic for MS inline asm. 425 void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred, 426 ExplodedNodeSet &Dst); 427 428 /// VisitBlockExpr - Transfer function logic for BlockExprs. 429 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 430 ExplodedNodeSet &Dst); 431 432 /// VisitLambdaExpr - Transfer function logic for LambdaExprs. 433 void VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred, 434 ExplodedNodeSet &Dst); 435 436 /// VisitBinaryOperator - Transfer function logic for binary operators. 437 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred, 438 ExplodedNodeSet &Dst); 439 440 441 /// VisitCall - Transfer function for function calls. 442 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 443 ExplodedNodeSet &Dst); 444 445 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 446 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 447 ExplodedNodeSet &Dst); 448 449 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 450 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 451 ExplodedNode *Pred, ExplodedNodeSet &Dst); 452 453 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 454 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D, 455 ExplodedNode *Pred, ExplodedNodeSet &Dst); 456 457 /// VisitDeclStmt - Transfer function logic for DeclStmts. 458 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 459 ExplodedNodeSet &Dst); 460 461 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 462 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R, 463 ExplodedNode *Pred, ExplodedNodeSet &Dst); 464 465 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred, 466 ExplodedNodeSet &Dst); 467 468 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 469 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 470 ExplodedNodeSet &Dst); 471 472 /// VisitMemberExpr - Transfer function for member expressions. 473 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred, 474 ExplodedNodeSet &Dst); 475 476 /// VisitAtomicExpr - Transfer function for builtin atomic expressions 477 void VisitAtomicExpr(const AtomicExpr *E, ExplodedNode *Pred, 478 ExplodedNodeSet &Dst); 479 480 /// Transfer function logic for ObjCAtSynchronizedStmts. 481 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 482 ExplodedNode *Pred, ExplodedNodeSet &Dst); 483 484 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 485 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred, 486 ExplodedNodeSet &Dst); 487 488 /// VisitObjCForCollectionStmt - Transfer function logic for 489 /// ObjCForCollectionStmt. 490 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S, 491 ExplodedNode *Pred, ExplodedNodeSet &Dst); 492 493 void VisitObjCMessage(const ObjCMessageExpr *ME, ExplodedNode *Pred, 494 ExplodedNodeSet &Dst); 495 496 /// VisitReturnStmt - Transfer function logic for return statements. 497 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred, 498 ExplodedNodeSet &Dst); 499 500 /// VisitOffsetOfExpr - Transfer function for offsetof. 501 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred, 502 ExplodedNodeSet &Dst); 503 504 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 505 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 506 ExplodedNode *Pred, ExplodedNodeSet &Dst); 507 508 /// VisitUnaryOperator - Transfer function logic for unary operators. 509 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred, 510 ExplodedNodeSet &Dst); 511 512 /// Handle ++ and -- (both pre- and post-increment). 513 void VisitIncrementDecrementOperator(const UnaryOperator* U, 514 ExplodedNode *Pred, 515 ExplodedNodeSet &Dst); 516 517 void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE, 518 ExplodedNodeSet &PreVisit, 519 ExplodedNodeSet &Dst); 520 521 void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred, 522 ExplodedNodeSet &Dst); 523 524 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 525 ExplodedNodeSet & Dst); 526 527 void VisitCXXConstructExpr(const CXXConstructExpr *E, ExplodedNode *Pred, 528 ExplodedNodeSet &Dst); 529 530 void VisitCXXDestructor(QualType ObjectType, const MemRegion *Dest, 531 const Stmt *S, bool IsBaseDtor, 532 ExplodedNode *Pred, ExplodedNodeSet &Dst, 533 EvalCallOptions &Options); 534 535 void VisitCXXNewAllocatorCall(const CXXNewExpr *CNE, 536 ExplodedNode *Pred, 537 ExplodedNodeSet &Dst); 538 539 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 540 ExplodedNodeSet &Dst); 541 542 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 543 ExplodedNodeSet &Dst); 544 545 /// Create a C++ temporary object for an rvalue. 546 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 547 ExplodedNode *Pred, 548 ExplodedNodeSet &Dst); 549 550 /// evalEagerlyAssumeBinOpBifurcation - Given the nodes in 'Src', eagerly assume symbolic 551 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 552 /// with those assumptions. 553 void evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 554 const Expr *Ex); 555 556 static std::pair<const ProgramPointTag *, const ProgramPointTag *> 557 geteagerlyAssumeBinOpBifurcationTags(); 558 559 SVal evalMinus(SVal X) { 560 return X.isValid() ? svalBuilder.evalMinus(X.castAs<NonLoc>()) : X; 561 } 562 563 SVal evalComplement(SVal X) { 564 return X.isValid() ? svalBuilder.evalComplement(X.castAs<NonLoc>()) : X; 565 } 566 567 ProgramStateRef handleLValueBitCast(ProgramStateRef state, const Expr *Ex, 568 const LocationContext *LCtx, QualType T, 569 QualType ExTy, const CastExpr *CastE, 570 StmtNodeBuilder &Bldr, 571 ExplodedNode *Pred); 572 573 ProgramStateRef handleLVectorSplat(ProgramStateRef state, 574 const LocationContext *LCtx, 575 const CastExpr *CastE, 576 StmtNodeBuilder &Bldr, 577 ExplodedNode *Pred); 578 579 void handleUOExtension(ExplodedNodeSet::iterator I, 580 const UnaryOperator* U, 581 StmtNodeBuilder &Bldr); 582 583public: 584 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, 585 NonLoc L, NonLoc R, QualType T) { 586 return svalBuilder.evalBinOpNN(state, op, L, R, T); 587 } 588 589 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, 590 NonLoc L, SVal R, QualType T) { 591 return R.isValid() ? svalBuilder.evalBinOpNN(state, op, L, 592 R.castAs<NonLoc>(), T) : R; 593 } 594 595 SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op, 596 SVal LHS, SVal RHS, QualType T) { 597 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 598 } 599 600 /// By looking at a certain item that may be potentially part of an object's 601 /// ConstructionContext, retrieve such object's location. A particular 602 /// statement can be transparently passed as \p Item in most cases. 603 static Optional<SVal> 604 getObjectUnderConstruction(ProgramStateRef State, 605 const ConstructionContextItem &Item, 606 const LocationContext *LC); 607 608protected: 609 /// evalBind - Handle the semantics of binding a value to a specific location. 610 /// This method is used by evalStore, VisitDeclStmt, and others. 611 void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred, 612 SVal location, SVal Val, bool atDeclInit = false, 613 const ProgramPoint *PP = nullptr); 614 615 /// Call PointerEscape callback when a value escapes as a result of bind. 616 ProgramStateRef processPointerEscapedOnBind( 617 ProgramStateRef State, ArrayRef<std::pair<SVal, SVal>> LocAndVals, 618 const LocationContext *LCtx, PointerEscapeKind Kind, 619 const CallEvent *Call) override; 620 621 ProgramStateRef 622 processPointerEscapedOnBind(ProgramStateRef State, 623 SVal Loc, SVal Val, 624 const LocationContext *LCtx); 625 626 /// Call PointerEscape callback when a value escapes as a result of 627 /// region invalidation. 628 /// \param[in] ITraits Specifies invalidation traits for regions/symbols. 629 ProgramStateRef notifyCheckersOfPointerEscape( 630 ProgramStateRef State, 631 const InvalidatedSymbols *Invalidated, 632 ArrayRef<const MemRegion *> ExplicitRegions, 633 const CallEvent *Call, 634 RegionAndSymbolInvalidationTraits &ITraits) override; 635 636 /// A simple wrapper when you only need to notify checkers of pointer-escape 637 /// of some values. 638 ProgramStateRef escapeValues(ProgramStateRef State, ArrayRef<SVal> Vs, 639 PointerEscapeKind K, 640 const CallEvent *Call = nullptr) const; 641 642public: 643 // FIXME: 'tag' should be removed, and a LocationContext should be used 644 // instead. 645 // FIXME: Comment on the meaning of the arguments, when 'St' may not 646 // be the same as Pred->state, and when 'location' may not be the 647 // same as state->getLValue(Ex). 648 /// Simulate a read of the result of Ex. 649 void evalLoad(ExplodedNodeSet &Dst, 650 const Expr *NodeEx, /* Eventually will be a CFGStmt */ 651 const Expr *BoundExpr, 652 ExplodedNode *Pred, 653 ProgramStateRef St, 654 SVal location, 655 const ProgramPointTag *tag = nullptr, 656 QualType LoadTy = QualType()); 657 658 // FIXME: 'tag' should be removed, and a LocationContext should be used 659 // instead. 660 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE, 661 ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val, 662 const ProgramPointTag *tag = nullptr); 663 664 /// Return the CFG element corresponding to the worklist element 665 /// that is currently being processed by ExprEngine. 666 CFGElement getCurrentCFGElement() { 667 return (*currBldrCtx->getBlock())[currStmtIdx]; 668 } 669 670 /// Create a new state in which the call return value is binded to the 671 /// call origin expression. 672 ProgramStateRef bindReturnValue(const CallEvent &Call, 673 const LocationContext *LCtx, 674 ProgramStateRef State); 675 676 /// Evaluate a call, running pre- and post-call checkers and allowing checkers 677 /// to be responsible for handling the evaluation of the call itself. 678 void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred, 679 const CallEvent &Call); 680 681 /// Default implementation of call evaluation. 682 void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred, 683 const CallEvent &Call, 684 const EvalCallOptions &CallOpts = {}); 685 686private: 687 ProgramStateRef finishArgumentConstruction(ProgramStateRef State, 688 const CallEvent &Call); 689 void finishArgumentConstruction(ExplodedNodeSet &Dst, ExplodedNode *Pred, 690 const CallEvent &Call); 691 692 void evalLoadCommon(ExplodedNodeSet &Dst, 693 const Expr *NodeEx, /* Eventually will be a CFGStmt */ 694 const Expr *BoundEx, 695 ExplodedNode *Pred, 696 ProgramStateRef St, 697 SVal location, 698 const ProgramPointTag *tag, 699 QualType LoadTy); 700 701 void evalLocation(ExplodedNodeSet &Dst, 702 const Stmt *NodeEx, /* This will eventually be a CFGStmt */ 703 const Stmt *BoundEx, 704 ExplodedNode *Pred, 705 ProgramStateRef St, 706 SVal location, 707 bool isLoad); 708 709 /// Count the stack depth and determine if the call is recursive. 710 void examineStackFrames(const Decl *D, const LocationContext *LCtx, 711 bool &IsRecursive, unsigned &StackDepth); 712 713 enum CallInlinePolicy { 714 CIP_Allowed, 715 CIP_DisallowedOnce, 716 CIP_DisallowedAlways 717 }; 718 719 /// See if a particular call should be inlined, by only looking 720 /// at the call event and the current state of analysis. 721 CallInlinePolicy mayInlineCallKind(const CallEvent &Call, 722 const ExplodedNode *Pred, 723 AnalyzerOptions &Opts, 724 const EvalCallOptions &CallOpts); 725 726 /// See if the given AnalysisDeclContext is built for a function that we 727 /// should always inline simply because it's small enough. 728 /// Apart from "small" functions, we also have "large" functions 729 /// (cf. isLarge()), some of which are huge (cf. isHuge()), and we classify 730 /// the remaining functions as "medium". 731 bool isSmall(AnalysisDeclContext *ADC) const; 732 733 /// See if the given AnalysisDeclContext is built for a function that we 734 /// should inline carefully because it looks pretty large. 735 bool isLarge(AnalysisDeclContext *ADC) const; 736 737 /// See if the given AnalysisDeclContext is built for a function that we 738 /// should never inline because it's legit gigantic. 739 bool isHuge(AnalysisDeclContext *ADC) const; 740 741 /// See if the given AnalysisDeclContext is built for a function that we 742 /// should inline, just by looking at the declaration of the function. 743 bool mayInlineDecl(AnalysisDeclContext *ADC) const; 744 745 /// Checks our policies and decides weither the given call should be inlined. 746 bool shouldInlineCall(const CallEvent &Call, const Decl *D, 747 const ExplodedNode *Pred, 748 const EvalCallOptions &CallOpts = {}); 749 750 bool inlineCall(const CallEvent &Call, const Decl *D, NodeBuilder &Bldr, 751 ExplodedNode *Pred, ProgramStateRef State); 752 753 /// Conservatively evaluate call by invalidating regions and binding 754 /// a conjured return value. 755 void conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr, 756 ExplodedNode *Pred, ProgramStateRef State); 757 758 /// Either inline or process the call conservatively (or both), based 759 /// on DynamicDispatchBifurcation data. 760 void BifurcateCall(const MemRegion *BifurReg, 761 const CallEvent &Call, const Decl *D, NodeBuilder &Bldr, 762 ExplodedNode *Pred); 763 764 bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC); 765 766 /// Models a trivial copy or move constructor or trivial assignment operator 767 /// call with a simple bind. 768 void performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred, 769 const CallEvent &Call); 770 771 /// If the value of the given expression \p InitWithAdjustments is a NonLoc, 772 /// copy it into a new temporary object region, and replace the value of the 773 /// expression with that. 774 /// 775 /// If \p Result is provided, the new region will be bound to this expression 776 /// instead of \p InitWithAdjustments. 777 /// 778 /// Returns the temporary region with adjustments into the optional 779 /// OutRegionWithAdjustments out-parameter if a new region was indeed needed, 780 /// otherwise sets it to nullptr. 781 ProgramStateRef createTemporaryRegionIfNeeded( 782 ProgramStateRef State, const LocationContext *LC, 783 const Expr *InitWithAdjustments, const Expr *Result = nullptr, 784 const SubRegion **OutRegionWithAdjustments = nullptr); 785 786 /// Returns a region representing the first element of a (possibly 787 /// multi-dimensional) array, for the purposes of element construction or 788 /// destruction. 789 /// 790 /// On return, \p Ty will be set to the base type of the array. 791 /// 792 /// If the type is not an array type at all, the original value is returned. 793 /// Otherwise the "IsArray" flag is set. 794 static SVal makeZeroElementRegion(ProgramStateRef State, SVal LValue, 795 QualType &Ty, bool &IsArray); 796 797 /// For a DeclStmt or CXXInitCtorInitializer, walk backward in the current CFG 798 /// block to find the constructor expression that directly constructed into 799 /// the storage for this statement. Returns null if the constructor for this 800 /// statement created a temporary object region rather than directly 801 /// constructing into an existing region. 802 const CXXConstructExpr *findDirectConstructorForCurrentCFGElement(); 803 804 /// Update the program state with all the path-sensitive information 805 /// that's necessary to perform construction of an object with a given 806 /// syntactic construction context. If the construction context is unavailable 807 /// or unusable for any reason, a dummy temporary region is returned, and the 808 /// IsConstructorWithImproperlyModeledTargetRegion flag is set in \p CallOpts. 809 /// Returns the updated program state and the new object's this-region. 810 std::pair<ProgramStateRef, SVal> prepareForObjectConstruction( 811 const Expr *E, ProgramStateRef State, const LocationContext *LCtx, 812 const ConstructionContext *CC, EvalCallOptions &CallOpts); 813 814 /// Store the location of a C++ object corresponding to a statement 815 /// until the statement is actually encountered. For example, if a DeclStmt 816 /// has CXXConstructExpr as its initializer, the object would be considered 817 /// to be "under construction" between CXXConstructExpr and DeclStmt. 818 /// This allows, among other things, to keep bindings to variable's fields 819 /// made within the constructor alive until its declaration actually 820 /// goes into scope. 821 static ProgramStateRef 822 addObjectUnderConstruction(ProgramStateRef State, 823 const ConstructionContextItem &Item, 824 const LocationContext *LC, SVal V); 825 826 /// Mark the object sa fully constructed, cleaning up the state trait 827 /// that tracks objects under construction. 828 static ProgramStateRef 829 finishObjectConstruction(ProgramStateRef State, 830 const ConstructionContextItem &Item, 831 const LocationContext *LC); 832 833 /// If the given expression corresponds to a temporary that was used for 834 /// passing into an elidable copy/move constructor and that constructor 835 /// was actually elided, track that we also need to elide the destructor. 836 static ProgramStateRef elideDestructor(ProgramStateRef State, 837 const CXXBindTemporaryExpr *BTE, 838 const LocationContext *LC); 839 840 /// Stop tracking the destructor that corresponds to an elided constructor. 841 static ProgramStateRef 842 cleanupElidedDestructor(ProgramStateRef State, 843 const CXXBindTemporaryExpr *BTE, 844 const LocationContext *LC); 845 846 /// Returns true if the given expression corresponds to a temporary that 847 /// was constructed for passing into an elidable copy/move constructor 848 /// and that constructor was actually elided. 849 static bool isDestructorElided(ProgramStateRef State, 850 const CXXBindTemporaryExpr *BTE, 851 const LocationContext *LC); 852 853 /// Check if all objects under construction have been fully constructed 854 /// for the given context range (including FromLC, not including ToLC). 855 /// This is useful for assertions. Also checks if elided destructors 856 /// were cleaned up. 857 static bool areAllObjectsFullyConstructed(ProgramStateRef State, 858 const LocationContext *FromLC, 859 const LocationContext *ToLC); 860}; 861 862/// Traits for storing the call processing policy inside GDM. 863/// The GDM stores the corresponding CallExpr pointer. 864// FIXME: This does not use the nice trait macros because it must be accessible 865// from multiple translation units. 866struct ReplayWithoutInlining{}; 867template <> 868struct ProgramStateTrait<ReplayWithoutInlining> : 869 public ProgramStatePartialTrait<const void*> { 870 static void *GDMIndex(); 871}; 872 873} // namespace ento 874 875} // namespace clang 876 877#endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H 878