ExprEngine.h revision 829846b5002d7f8d6a54b9c58c3ecf7cac56d2cc
1//===-- ExprEngine.h - Path-Sensitive Expression-Level Dataflow ---*- C++ -*-=// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// This file defines a meta-engine for path-sensitive dataflow analysis that 11// is built on CoreEngine, but provides the boilerplate to execute transfer 12// functions and build the ExplodedGraph at the expression level. 13// 14//===----------------------------------------------------------------------===// 15 16#ifndef LLVM_CLANG_GR_EXPRENGINE 17#define LLVM_CLANG_GR_EXPRENGINE 18 19#include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h" 20#include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h" 21#include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h" 22#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h" 23#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h" 24#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 25#include "clang/AST/Expr.h" 26#include "clang/AST/Type.h" 27 28namespace clang { 29 30class AnalysisDeclContextManager; 31class CXXCatchStmt; 32class CXXConstructExpr; 33class CXXDeleteExpr; 34class CXXNewExpr; 35class CXXTemporaryObjectExpr; 36class CXXThisExpr; 37class MaterializeTemporaryExpr; 38class ObjCAtSynchronizedStmt; 39class ObjCForCollectionStmt; 40 41namespace ento { 42 43class AnalysisManager; 44class CallEvent; 45class SimpleCall; 46class ObjCMethodCall; 47 48class ExprEngine : public SubEngine { 49 AnalysisManager &AMgr; 50 51 AnalysisDeclContextManager &AnalysisDeclContexts; 52 53 CoreEngine Engine; 54 55 /// G - the simulation graph. 56 ExplodedGraph& G; 57 58 /// StateMgr - Object that manages the data for all created states. 59 ProgramStateManager StateMgr; 60 61 /// SymMgr - Object that manages the symbol information. 62 SymbolManager& SymMgr; 63 64 /// svalBuilder - SValBuilder object that creates SVals from expressions. 65 SValBuilder &svalBuilder; 66 67 /// EntryNode - The immediate predecessor node. 68 ExplodedNode *EntryNode; 69 70 /// CleanedState - The state for EntryNode "cleaned" of all dead 71 /// variables and symbols (as determined by a liveness analysis). 72 ProgramStateRef CleanedState; 73 74 /// currentStmt - The current block-level statement. 75 const Stmt *currentStmt; 76 unsigned int currentStmtIdx; 77 const NodeBuilderContext *currentBuilderContext; 78 79 /// Obj-C Class Identifiers. 80 IdentifierInfo* NSExceptionII; 81 82 /// Obj-C Selectors. 83 Selector* NSExceptionInstanceRaiseSelectors; 84 Selector RaiseSel; 85 86 /// Whether or not GC is enabled in this analysis. 87 bool ObjCGCEnabled; 88 89 /// The BugReporter associated with this engine. It is important that 90 /// this object be placed at the very end of member variables so that its 91 /// destructor is called before the rest of the ExprEngine is destroyed. 92 GRBugReporter BR; 93 94public: 95 ExprEngine(AnalysisManager &mgr, bool gcEnabled, 96 SetOfConstDecls *VisitedCallees, 97 FunctionSummariesTy *FS); 98 99 ~ExprEngine(); 100 101 /// Returns true if there is still simulation state on the worklist. 102 bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) { 103 return Engine.ExecuteWorkList(L, Steps, 0); 104 } 105 106 /// Execute the work list with an initial state. Nodes that reaches the exit 107 /// of the function are added into the Dst set, which represent the exit 108 /// state of the function call. Returns true if there is still simulation 109 /// state on the worklist. 110 bool ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps, 111 ProgramStateRef InitState, 112 ExplodedNodeSet &Dst) { 113 return Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst); 114 } 115 116 /// getContext - Return the ASTContext associated with this analysis. 117 ASTContext &getContext() const { return AMgr.getASTContext(); } 118 119 virtual AnalysisManager &getAnalysisManager() { return AMgr; } 120 121 CheckerManager &getCheckerManager() const { 122 return *AMgr.getCheckerManager(); 123 } 124 125 SValBuilder &getSValBuilder() { return svalBuilder; } 126 127 BugReporter& getBugReporter() { return BR; } 128 129 const NodeBuilderContext &getBuilderContext() { 130 assert(currentBuilderContext); 131 return *currentBuilderContext; 132 } 133 134 bool isObjCGCEnabled() { return ObjCGCEnabled; } 135 136 const Stmt *getStmt() const; 137 138 void GenerateAutoTransition(ExplodedNode *N); 139 void enqueueEndOfPath(ExplodedNodeSet &S); 140 void GenerateCallExitNode(ExplodedNode *N); 141 142 /// ViewGraph - Visualize the ExplodedGraph created by executing the 143 /// simulation. 144 void ViewGraph(bool trim = false); 145 146 void ViewGraph(ExplodedNode** Beg, ExplodedNode** End); 147 148 /// getInitialState - Return the initial state used for the root vertex 149 /// in the ExplodedGraph. 150 ProgramStateRef getInitialState(const LocationContext *InitLoc); 151 152 ExplodedGraph& getGraph() { return G; } 153 const ExplodedGraph& getGraph() const { return G; } 154 155 /// \brief Run the analyzer's garbage collection - remove dead symbols and 156 /// bindings. 157 /// 158 /// \param Node - The predecessor node, from which the processing should 159 /// start. 160 /// \param Out - The returned set of output nodes. 161 /// \param ReferenceStmt - Run garbage collection using the symbols, 162 /// which are live before the given statement. 163 /// \param LC - The location context of the ReferenceStmt. 164 /// \param DiagnosticStmt - the statement used to associate the diagnostic 165 /// message, if any warnings should occur while removing the dead (leaks 166 /// are usually reported here). 167 /// \param K - In some cases it is possible to use PreStmt kind. (Do 168 /// not use it unless you know what you are doing.) 169 void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out, 170 const Stmt *ReferenceStmt, const LocationContext *LC, 171 const Stmt *DiagnosticStmt, 172 ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind); 173 174 /// processCFGElement - Called by CoreEngine. Used to generate new successor 175 /// nodes by processing the 'effects' of a CFG element. 176 void processCFGElement(const CFGElement E, ExplodedNode *Pred, 177 unsigned StmtIdx, NodeBuilderContext *Ctx); 178 179 void ProcessStmt(const CFGStmt S, ExplodedNode *Pred); 180 181 void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred); 182 183 void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred); 184 185 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 186 ExplodedNode *Pred, ExplodedNodeSet &Dst); 187 void ProcessBaseDtor(const CFGBaseDtor D, 188 ExplodedNode *Pred, ExplodedNodeSet &Dst); 189 void ProcessMemberDtor(const CFGMemberDtor D, 190 ExplodedNode *Pred, ExplodedNodeSet &Dst); 191 void ProcessTemporaryDtor(const CFGTemporaryDtor D, 192 ExplodedNode *Pred, ExplodedNodeSet &Dst); 193 194 /// Called by CoreEngine when processing the entrance of a CFGBlock. 195 virtual void processCFGBlockEntrance(const BlockEdge &L, 196 NodeBuilderWithSinks &nodeBuilder); 197 198 /// ProcessBranch - Called by CoreEngine. Used to generate successor 199 /// nodes by processing the 'effects' of a branch condition. 200 void processBranch(const Stmt *Condition, const Stmt *Term, 201 NodeBuilderContext& BuilderCtx, 202 ExplodedNode *Pred, 203 ExplodedNodeSet &Dst, 204 const CFGBlock *DstT, 205 const CFGBlock *DstF); 206 207 /// processIndirectGoto - Called by CoreEngine. Used to generate successor 208 /// nodes by processing the 'effects' of a computed goto jump. 209 void processIndirectGoto(IndirectGotoNodeBuilder& builder); 210 211 /// ProcessSwitch - Called by CoreEngine. Used to generate successor 212 /// nodes by processing the 'effects' of a switch statement. 213 void processSwitch(SwitchNodeBuilder& builder); 214 215 /// ProcessEndPath - Called by CoreEngine. Used to generate end-of-path 216 /// nodes when the control reaches the end of a function. 217 void processEndOfFunction(NodeBuilderContext& BC); 218 219 /// Generate the entry node of the callee. 220 void processCallEnter(CallEnter CE, ExplodedNode *Pred); 221 222 /// Generate the sequence of nodes that simulate the call exit and the post 223 /// visit for CallExpr. 224 void processCallExit(ExplodedNode *Pred); 225 226 /// Called by CoreEngine when the analysis worklist has terminated. 227 void processEndWorklist(bool hasWorkRemaining); 228 229 /// evalAssume - Callback function invoked by the ConstraintManager when 230 /// making assumptions about state values. 231 ProgramStateRef processAssume(ProgramStateRef state, SVal cond,bool assumption); 232 233 /// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a 234 /// region change should trigger a processRegionChanges update. 235 bool wantsRegionChangeUpdate(ProgramStateRef state); 236 237 /// processRegionChanges - Called by ProgramStateManager whenever a change is made 238 /// to the store. Used to update checkers that track region values. 239 ProgramStateRef 240 processRegionChanges(ProgramStateRef state, 241 const StoreManager::InvalidatedSymbols *invalidated, 242 ArrayRef<const MemRegion *> ExplicitRegions, 243 ArrayRef<const MemRegion *> Regions, 244 const CallEvent *Call); 245 246 /// printState - Called by ProgramStateManager to print checker-specific data. 247 void printState(raw_ostream &Out, ProgramStateRef State, 248 const char *NL, const char *Sep); 249 250 virtual ProgramStateManager& getStateManager() { return StateMgr; } 251 252 StoreManager& getStoreManager() { return StateMgr.getStoreManager(); } 253 254 ConstraintManager& getConstraintManager() { 255 return StateMgr.getConstraintManager(); 256 } 257 258 // FIXME: Remove when we migrate over to just using SValBuilder. 259 BasicValueFactory& getBasicVals() { 260 return StateMgr.getBasicVals(); 261 } 262 const BasicValueFactory& getBasicVals() const { 263 return StateMgr.getBasicVals(); 264 } 265 266 // FIXME: Remove when we migrate over to just using ValueManager. 267 SymbolManager& getSymbolManager() { return SymMgr; } 268 const SymbolManager& getSymbolManager() const { return SymMgr; } 269 270 // Functions for external checking of whether we have unfinished work 271 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); } 272 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); } 273 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); } 274 275 const CoreEngine &getCoreEngine() const { return Engine; } 276 277public: 278 /// Visit - Transfer function logic for all statements. Dispatches to 279 /// other functions that handle specific kinds of statements. 280 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst); 281 282 /// VisitArraySubscriptExpr - Transfer function for array accesses. 283 void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr *Ex, 284 ExplodedNode *Pred, 285 ExplodedNodeSet &Dst); 286 287 /// VisitAsmStmt - Transfer function logic for inline asm. 288 void VisitAsmStmt(const AsmStmt *A, ExplodedNode *Pred, ExplodedNodeSet &Dst); 289 290 /// VisitMSAsmStmt - Transfer function logic for MS inline asm. 291 void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred, 292 ExplodedNodeSet &Dst); 293 294 /// VisitBlockExpr - Transfer function logic for BlockExprs. 295 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 296 ExplodedNodeSet &Dst); 297 298 /// VisitBinaryOperator - Transfer function logic for binary operators. 299 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred, 300 ExplodedNodeSet &Dst); 301 302 303 /// VisitCall - Transfer function for function calls. 304 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 305 ExplodedNodeSet &Dst); 306 307 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 308 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 309 ExplodedNodeSet &Dst); 310 311 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 312 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 313 ExplodedNode *Pred, ExplodedNodeSet &Dst); 314 315 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 316 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D, 317 ExplodedNode *Pred, ExplodedNodeSet &Dst); 318 319 /// VisitDeclStmt - Transfer function logic for DeclStmts. 320 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 321 ExplodedNodeSet &Dst); 322 323 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 324 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R, 325 ExplodedNode *Pred, ExplodedNodeSet &Dst); 326 327 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred, 328 ExplodedNodeSet &Dst); 329 330 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 331 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 332 ExplodedNodeSet &Dst); 333 334 /// VisitMemberExpr - Transfer function for member expressions. 335 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred, 336 ExplodedNodeSet &Dst); 337 338 /// Transfer function logic for ObjCAtSynchronizedStmts. 339 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 340 ExplodedNode *Pred, ExplodedNodeSet &Dst); 341 342 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 343 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred, 344 ExplodedNodeSet &Dst); 345 346 /// VisitObjCForCollectionStmt - Transfer function logic for 347 /// ObjCForCollectionStmt. 348 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S, 349 ExplodedNode *Pred, ExplodedNodeSet &Dst); 350 351 void VisitObjCMessage(const ObjCMethodCall &Msg, ExplodedNode *Pred, 352 ExplodedNodeSet &Dst); 353 354 /// VisitReturnStmt - Transfer function logic for return statements. 355 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred, 356 ExplodedNodeSet &Dst); 357 358 /// VisitOffsetOfExpr - Transfer function for offsetof. 359 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred, 360 ExplodedNodeSet &Dst); 361 362 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 363 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 364 ExplodedNode *Pred, ExplodedNodeSet &Dst); 365 366 /// VisitUnaryOperator - Transfer function logic for unary operators. 367 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred, 368 ExplodedNodeSet &Dst); 369 370 /// Handle ++ and -- (both pre- and post-increment). 371 void VisitIncrementDecrementOperator(const UnaryOperator* U, 372 ExplodedNode *Pred, 373 ExplodedNodeSet &Dst); 374 375 void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred, 376 ExplodedNodeSet &Dst); 377 378 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 379 ExplodedNodeSet & Dst); 380 381 void VisitCXXConstructExpr(const CXXConstructExpr *E, const MemRegion *Dest, 382 ExplodedNode *Pred, ExplodedNodeSet &Dst); 383 384 void VisitCXXDestructor(const CXXDestructorDecl *DD, 385 const MemRegion *Dest, const Stmt *S, 386 ExplodedNode *Pred, ExplodedNodeSet &Dst); 387 388 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 389 ExplodedNodeSet &Dst); 390 391 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 392 ExplodedNodeSet &Dst); 393 394 /// Create a C++ temporary object for an rvalue. 395 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 396 ExplodedNode *Pred, 397 ExplodedNodeSet &Dst); 398 399 /// evalEagerlyAssume - Given the nodes in 'Src', eagerly assume symbolic 400 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 401 /// with those assumptions. 402 void evalEagerlyAssume(ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 403 const Expr *Ex); 404 405 std::pair<const ProgramPointTag *, const ProgramPointTag*> 406 getEagerlyAssumeTags(); 407 408 SVal evalMinus(SVal X) { 409 return X.isValid() ? svalBuilder.evalMinus(cast<NonLoc>(X)) : X; 410 } 411 412 SVal evalComplement(SVal X) { 413 return X.isValid() ? svalBuilder.evalComplement(cast<NonLoc>(X)) : X; 414 } 415 416public: 417 418 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, 419 NonLoc L, NonLoc R, QualType T) { 420 return svalBuilder.evalBinOpNN(state, op, L, R, T); 421 } 422 423 SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op, 424 NonLoc L, SVal R, QualType T) { 425 return R.isValid() ? svalBuilder.evalBinOpNN(state,op,L, cast<NonLoc>(R), T) : R; 426 } 427 428 SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op, 429 SVal LHS, SVal RHS, QualType T) { 430 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 431 } 432 433protected: 434 void evalObjCMessage(StmtNodeBuilder &Bldr, const ObjCMethodCall &Msg, 435 ExplodedNode *Pred, ProgramStateRef state, 436 bool GenSink); 437 438 /// evalBind - Handle the semantics of binding a value to a specific location. 439 /// This method is used by evalStore, VisitDeclStmt, and others. 440 void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred, 441 SVal location, SVal Val, bool atDeclInit = false); 442 443public: 444 // FIXME: 'tag' should be removed, and a LocationContext should be used 445 // instead. 446 // FIXME: Comment on the meaning of the arguments, when 'St' may not 447 // be the same as Pred->state, and when 'location' may not be the 448 // same as state->getLValue(Ex). 449 /// Simulate a read of the result of Ex. 450 void evalLoad(ExplodedNodeSet &Dst, 451 const Expr *NodeEx, /* Eventually will be a CFGStmt */ 452 const Expr *BoundExpr, 453 ExplodedNode *Pred, 454 ProgramStateRef St, 455 SVal location, 456 const ProgramPointTag *tag = 0, 457 QualType LoadTy = QualType()); 458 459 // FIXME: 'tag' should be removed, and a LocationContext should be used 460 // instead. 461 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE, 462 ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val, 463 const ProgramPointTag *tag = 0); 464 465 /// \brief Create a new state in which the call return value is binded to the 466 /// call origin expression. 467 ProgramStateRef bindReturnValue(const CallEvent &Call, 468 const LocationContext *LCtx, 469 ProgramStateRef State); 470 471 void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred, 472 const SimpleCall &Call); 473 474 /// \bried Default implementation of call evaluation. 475 void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred, 476 const CallEvent &Call); 477private: 478 void evalLoadCommon(ExplodedNodeSet &Dst, 479 const Expr *NodeEx, /* Eventually will be a CFGStmt */ 480 const Expr *BoundEx, 481 ExplodedNode *Pred, 482 ProgramStateRef St, 483 SVal location, 484 const ProgramPointTag *tag, 485 QualType LoadTy); 486 487 // FIXME: 'tag' should be removed, and a LocationContext should be used 488 // instead. 489 void evalLocation(ExplodedNodeSet &Dst, 490 const Stmt *NodeEx, /* This will eventually be a CFGStmt */ 491 const Stmt *BoundEx, 492 ExplodedNode *Pred, 493 ProgramStateRef St, SVal location, 494 const ProgramPointTag *tag, bool isLoad); 495 496 bool shouldInlineDecl(const Decl *D, ExplodedNode *Pred); 497 bool inlineCall(const CallEvent &Call, ExplodedNode *Pred); 498 499 bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC); 500}; 501 502/// Traits for storing the call processing policy inside GDM. 503/// The GDM stores the corresponding CallExpr pointer. 504struct ReplayWithoutInlining{}; 505template <> 506struct ProgramStateTrait<ReplayWithoutInlining> : 507 public ProgramStatePartialTrait<void*> { 508 static void *GDMIndex() { static int index = 0; return &index; } 509}; 510 511} // end ento namespace 512 513} // end clang namespace 514 515#endif 516