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/BugReporter/BugReporter.h" 24 #include "clang/AST/Type.h" 25 #include "clang/AST/ExprObjC.h" 26 #include "clang/AST/ExprCXX.h" 27 #include "clang/AST/StmtObjC.h" 28 29 namespace clang { 30 31 class ObjCForCollectionStmt; 32 33 namespace ento { 34 35 class AnalysisManager; 36 class CallOrObjCMessage; 37 class ObjCMessage; 38 39 class ExprEngine : public SubEngine { 40 AnalysisManager &AMgr; 41 42 CoreEngine Engine; 43 44 /// G - the simulation graph. 45 ExplodedGraph& G; 46 47 /// Builder - The current StmtNodeBuilder which is used when building the 48 /// nodes for a given statement. 49 StmtNodeBuilder* Builder; 50 51 /// StateMgr - Object that manages the data for all created states. 52 ProgramStateManager StateMgr; 53 54 /// SymMgr - Object that manages the symbol information. 55 SymbolManager& SymMgr; 56 57 /// svalBuilder - SValBuilder object that creates SVals from expressions. 58 SValBuilder &svalBuilder; 59 60 /// EntryNode - The immediate predecessor node. 61 ExplodedNode *EntryNode; 62 63 /// CleanedState - The state for EntryNode "cleaned" of all dead 64 /// variables and symbols (as determined by a liveness analysis). 65 const ProgramState *CleanedState; 66 67 /// currentStmt - The current block-level statement. 68 const Stmt *currentStmt; 69 70 /// Obj-C Class Identifiers. 71 IdentifierInfo* NSExceptionII; 72 73 /// Obj-C Selectors. 74 Selector* NSExceptionInstanceRaiseSelectors; 75 Selector RaiseSel; 76 77 /// Whether or not GC is enabled in this analysis. 78 bool ObjCGCEnabled; 79 80 /// The BugReporter associated with this engine. It is important that 81 /// this object be placed at the very end of member variables so that its 82 /// destructor is called before the rest of the ExprEngine is destroyed. 83 GRBugReporter BR; 84 85 public: 86 ExprEngine(AnalysisManager &mgr, bool gcEnabled); 87 88 ~ExprEngine(); 89 90 void ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) { 91 Engine.ExecuteWorkList(L, Steps, 0); 92 } 93 94 /// Execute the work list with an initial state. Nodes that reaches the exit 95 /// of the function are added into the Dst set, which represent the exit 96 /// state of the function call. 97 void ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps, 98 const ProgramState *InitState, 99 ExplodedNodeSet &Dst) { 100 Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst); 101 } 102 103 /// getContext - Return the ASTContext associated with this analysis. 104 ASTContext &getContext() const { return AMgr.getASTContext(); } 105 106 virtual AnalysisManager &getAnalysisManager() { return AMgr; } 107 108 CheckerManager &getCheckerManager() const { 109 return *AMgr.getCheckerManager(); 110 } 111 112 SValBuilder &getSValBuilder() { return svalBuilder; } 113 114 BugReporter& getBugReporter() { return BR; } 115 116 StmtNodeBuilder &getBuilder() { assert(Builder); return *Builder; } 117 118 bool isObjCGCEnabled() { return ObjCGCEnabled; } 119 120 /// ViewGraph - Visualize the ExplodedGraph created by executing the 121 /// simulation. 122 void ViewGraph(bool trim = false); 123 124 void ViewGraph(ExplodedNode** Beg, ExplodedNode** End); 125 126 /// getInitialState - Return the initial state used for the root vertex 127 /// in the ExplodedGraph. 128 const ProgramState *getInitialState(const LocationContext *InitLoc); 129 130 ExplodedGraph& getGraph() { return G; } 131 const ExplodedGraph& getGraph() const { return G; } 132 133 /// processCFGElement - Called by CoreEngine. Used to generate new successor 134 /// nodes by processing the 'effects' of a CFG element. 135 void processCFGElement(const CFGElement E, StmtNodeBuilder& Bldr, 136 ExplodedNode *Pred); 137 138 void ProcessStmt(const CFGStmt S, StmtNodeBuilder &builder, 139 ExplodedNode *Pred); 140 141 void ProcessInitializer(const CFGInitializer I, StmtNodeBuilder &Bldr, 142 ExplodedNode *Pred); 143 144 void ProcessImplicitDtor(const CFGImplicitDtor D, StmtNodeBuilder &builder, 145 ExplodedNode *Pred); 146 147 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 148 StmtNodeBuilder &builder, ExplodedNode *Pred); 149 void ProcessBaseDtor(const CFGBaseDtor D, StmtNodeBuilder &builder); 150 void ProcessMemberDtor(const CFGMemberDtor D, StmtNodeBuilder &builder); 151 void ProcessTemporaryDtor(const CFGTemporaryDtor D, 152 StmtNodeBuilder &builder); 153 154 /// Called by CoreEngine when processing the entrance of a CFGBlock. 155 virtual void processCFGBlockEntrance(ExplodedNodeSet &dstNodes, 156 GenericNodeBuilder<BlockEntrance> &nodeBuilder); 157 158 /// ProcessBranch - Called by CoreEngine. Used to generate successor 159 /// nodes by processing the 'effects' of a branch condition. 160 void processBranch(const Stmt *Condition, const Stmt *Term, 161 NodeBuilderContext& BuilderCtx, 162 ExplodedNode *Pred, 163 const CFGBlock *DstT, 164 const CFGBlock *DstF); 165 166 /// processIndirectGoto - Called by CoreEngine. Used to generate successor 167 /// nodes by processing the 'effects' of a computed goto jump. 168 void processIndirectGoto(IndirectGotoNodeBuilder& builder); 169 170 /// ProcessSwitch - Called by CoreEngine. Used to generate successor 171 /// nodes by processing the 'effects' of a switch statement. 172 void processSwitch(SwitchNodeBuilder& builder); 173 174 /// ProcessEndPath - Called by CoreEngine. Used to generate end-of-path 175 /// nodes when the control reaches the end of a function. 176 void processEndOfFunction(EndOfFunctionNodeBuilder& builder); 177 178 /// Generate the entry node of the callee. 179 void processCallEnter(CallEnterNodeBuilder &builder); 180 181 /// Generate the first post callsite node. 182 void processCallExit(CallExitNodeBuilder &builder); 183 184 /// Called by CoreEngine when the analysis worklist has terminated. 185 void processEndWorklist(bool hasWorkRemaining); 186 187 /// evalAssume - Callback function invoked by the ConstraintManager when 188 /// making assumptions about state values. 189 const ProgramState *processAssume(const ProgramState *state, SVal cond,bool assumption); 190 191 /// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a 192 /// region change should trigger a processRegionChanges update. 193 bool wantsRegionChangeUpdate(const ProgramState *state); 194 195 /// processRegionChanges - Called by ProgramStateManager whenever a change is made 196 /// to the store. Used to update checkers that track region values. 197 const ProgramState * 198 processRegionChanges(const ProgramState *state, 199 const StoreManager::InvalidatedSymbols *invalidated, 200 ArrayRef<const MemRegion *> ExplicitRegions, 201 ArrayRef<const MemRegion *> Regions); 202 203 /// printState - Called by ProgramStateManager to print checker-specific data. 204 void printState(raw_ostream &Out, const ProgramState *State, 205 const char *NL, const char *Sep); 206 207 virtual ProgramStateManager& getStateManager() { return StateMgr; } 208 209 StoreManager& getStoreManager() { return StateMgr.getStoreManager(); } 210 211 ConstraintManager& getConstraintManager() { 212 return StateMgr.getConstraintManager(); 213 } 214 215 // FIXME: Remove when we migrate over to just using SValBuilder. 216 BasicValueFactory& getBasicVals() { 217 return StateMgr.getBasicVals(); 218 } 219 const BasicValueFactory& getBasicVals() const { 220 return StateMgr.getBasicVals(); 221 } 222 223 // FIXME: Remove when we migrate over to just using ValueManager. 224 SymbolManager& getSymbolManager() { return SymMgr; } 225 const SymbolManager& getSymbolManager() const { return SymMgr; } 226 227 // Functions for external checking of whether we have unfinished work 228 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); } 229 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); } 230 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); } 231 232 const CoreEngine &getCoreEngine() const { return Engine; } 233 234 public: 235 ExplodedNode *MakeNode(ExplodedNodeSet &Dst, const Stmt *S, 236 ExplodedNode *Pred, const ProgramState *St, 237 ProgramPoint::Kind K = ProgramPoint::PostStmtKind, 238 const ProgramPointTag *tag = 0); 239 240 /// Visit - Transfer function logic for all statements. Dispatches to 241 /// other functions that handle specific kinds of statements. 242 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst); 243 244 /// VisitArraySubscriptExpr - Transfer function for array accesses. 245 void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr *Ex, 246 ExplodedNode *Pred, 247 ExplodedNodeSet &Dst); 248 249 /// VisitAsmStmt - Transfer function logic for inline asm. 250 void VisitAsmStmt(const AsmStmt *A, ExplodedNode *Pred, ExplodedNodeSet &Dst); 251 252 void VisitAsmStmtHelperOutputs(const AsmStmt *A, 253 AsmStmt::const_outputs_iterator I, 254 AsmStmt::const_outputs_iterator E, 255 ExplodedNode *Pred, ExplodedNodeSet &Dst); 256 257 void VisitAsmStmtHelperInputs(const AsmStmt *A, 258 AsmStmt::const_inputs_iterator I, 259 AsmStmt::const_inputs_iterator E, 260 ExplodedNode *Pred, ExplodedNodeSet &Dst); 261 262 /// VisitBlockExpr - Transfer function logic for BlockExprs. 263 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 264 ExplodedNodeSet &Dst); 265 266 /// VisitBinaryOperator - Transfer function logic for binary operators. 267 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred, 268 ExplodedNodeSet &Dst); 269 270 271 /// VisitCall - Transfer function for function calls. 272 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 273 ExplodedNodeSet &Dst); 274 275 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 276 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 277 ExplodedNodeSet &Dst); 278 279 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 280 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 281 ExplodedNode *Pred, ExplodedNodeSet &Dst); 282 283 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 284 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D, 285 ExplodedNode *Pred, ExplodedNodeSet &Dst); 286 287 /// VisitDeclStmt - Transfer function logic for DeclStmts. 288 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 289 ExplodedNodeSet &Dst); 290 291 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 292 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R, 293 ExplodedNode *Pred, ExplodedNodeSet &Dst); 294 295 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred, 296 ExplodedNodeSet &Dst); 297 298 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 299 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 300 ExplodedNodeSet &Dst); 301 302 /// VisitMemberExpr - Transfer function for member expressions. 303 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred, 304 ExplodedNodeSet &Dst); 305 306 /// Transfer function logic for ObjCAtSynchronizedStmts. 307 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 308 ExplodedNode *Pred, ExplodedNodeSet &Dst); 309 310 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 311 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred, 312 ExplodedNodeSet &Dst); 313 314 /// VisitObjCForCollectionStmt - Transfer function logic for 315 /// ObjCForCollectionStmt. 316 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S, 317 ExplodedNode *Pred, ExplodedNodeSet &Dst); 318 319 void VisitObjCMessage(const ObjCMessage &msg, ExplodedNode *Pred, 320 ExplodedNodeSet &Dst); 321 322 /// VisitReturnStmt - Transfer function logic for return statements. 323 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred, 324 ExplodedNodeSet &Dst); 325 326 /// VisitOffsetOfExpr - Transfer function for offsetof. 327 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred, 328 ExplodedNodeSet &Dst); 329 330 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 331 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 332 ExplodedNode *Pred, ExplodedNodeSet &Dst); 333 334 /// VisitUnaryOperator - Transfer function logic for unary operators. 335 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred, 336 ExplodedNodeSet &Dst); 337 338 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 339 ExplodedNodeSet & Dst); 340 341 void VisitCXXTemporaryObjectExpr(const CXXTemporaryObjectExpr *expr, 342 ExplodedNode *Pred, ExplodedNodeSet &Dst) { 343 VisitCXXConstructExpr(expr, 0, Pred, Dst); 344 } 345 346 void VisitCXXConstructExpr(const CXXConstructExpr *E, const MemRegion *Dest, 347 ExplodedNode *Pred, ExplodedNodeSet &Dst); 348 349 void VisitCXXDestructor(const CXXDestructorDecl *DD, 350 const MemRegion *Dest, const Stmt *S, 351 ExplodedNode *Pred, ExplodedNodeSet &Dst); 352 353 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 354 ExplodedNodeSet &Dst); 355 356 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 357 ExplodedNodeSet &Dst); 358 359 void VisitAggExpr(const Expr *E, const MemRegion *Dest, ExplodedNode *Pred, 360 ExplodedNodeSet &Dst); 361 362 /// Create a C++ temporary object for an rvalue. 363 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 364 ExplodedNode *Pred, 365 ExplodedNodeSet &Dst); 366 367 /// Synthesize CXXThisRegion. 368 const CXXThisRegion *getCXXThisRegion(const CXXRecordDecl *RD, 369 const StackFrameContext *SFC); 370 371 const CXXThisRegion *getCXXThisRegion(const CXXMethodDecl *decl, 372 const StackFrameContext *frameCtx); 373 374 /// Evaluate arguments with a work list algorithm. 375 void evalArguments(ConstExprIterator AI, ConstExprIterator AE, 376 const FunctionProtoType *FnType, 377 ExplodedNode *Pred, ExplodedNodeSet &Dst, 378 bool FstArgAsLValue = false); 379 380 /// Evaluate callee expression (for a function call). 381 void evalCallee(const CallExpr *callExpr, const ExplodedNodeSet &src, 382 ExplodedNodeSet &dest); 383 384 /// evalEagerlyAssume - Given the nodes in 'Src', eagerly assume symbolic 385 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 386 /// with those assumptions. 387 void evalEagerlyAssume(ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 388 const Expr *Ex); 389 390 std::pair<const ProgramPointTag *, const ProgramPointTag*> 391 getEagerlyAssumeTags(); 392 393 SVal evalMinus(SVal X) { 394 return X.isValid() ? svalBuilder.evalMinus(cast<NonLoc>(X)) : X; 395 } 396 397 SVal evalComplement(SVal X) { 398 return X.isValid() ? svalBuilder.evalComplement(cast<NonLoc>(X)) : X; 399 } 400 401 public: 402 403 SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op, 404 NonLoc L, NonLoc R, QualType T) { 405 return svalBuilder.evalBinOpNN(state, op, L, R, T); 406 } 407 408 SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op, 409 NonLoc L, SVal R, QualType T) { 410 return R.isValid() ? svalBuilder.evalBinOpNN(state,op,L, cast<NonLoc>(R), T) : R; 411 } 412 413 SVal evalBinOp(const ProgramState *ST, BinaryOperator::Opcode Op, 414 SVal LHS, SVal RHS, QualType T) { 415 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 416 } 417 418 protected: 419 void evalObjCMessage(ExplodedNodeSet &Dst, const ObjCMessage &msg, 420 ExplodedNode *Pred, const ProgramState *state); 421 422 const ProgramState *invalidateArguments(const ProgramState *State, 423 const CallOrObjCMessage &Call, 424 const LocationContext *LC); 425 426 const ProgramState *MarkBranch(const ProgramState *St, const Stmt *Terminator, 427 bool branchTaken); 428 429 /// evalBind - Handle the semantics of binding a value to a specific location. 430 /// This method is used by evalStore, VisitDeclStmt, and others. 431 void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred, 432 SVal location, SVal Val, bool atDeclInit = false); 433 434 public: 435 // FIXME: 'tag' should be removed, and a LocationContext should be used 436 // instead. 437 // FIXME: Comment on the meaning of the arguments, when 'St' may not 438 // be the same as Pred->state, and when 'location' may not be the 439 // same as state->getLValue(Ex). 440 /// Simulate a read of the result of Ex. 441 void evalLoad(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred, 442 const ProgramState *St, SVal location, const ProgramPointTag *tag = 0, 443 QualType LoadTy = QualType()); 444 445 // FIXME: 'tag' should be removed, and a LocationContext should be used 446 // instead. 447 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE, 448 ExplodedNode *Pred, const ProgramState *St, SVal TargetLV, SVal Val, 449 const ProgramPointTag *tag = 0); 450 private: 451 void evalLoadCommon(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred, 452 const ProgramState *St, SVal location, const ProgramPointTag *tag, 453 QualType LoadTy); 454 455 // FIXME: 'tag' should be removed, and a LocationContext should be used 456 // instead. 457 void evalLocation(ExplodedNodeSet &Dst, const Stmt *S, ExplodedNode *Pred, 458 const ProgramState *St, SVal location, 459 const ProgramPointTag *tag, bool isLoad); 460 461 bool InlineCall(ExplodedNodeSet &Dst, const CallExpr *CE, ExplodedNode *Pred); 462 463 464 public: 465 /// Returns true if calling the specific function or method would possibly 466 /// cause global variables to be invalidated. 467 bool doesInvalidateGlobals(const CallOrObjCMessage &callOrMessage) const; 468 469 }; 470 471 } // end ento namespace 472 473 } // end clang namespace 474 475 #endif 476
