ExprEngine.h revision 056c4b46335a3bd2612414735d5749ee159c0165
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 29namespace clang { 30 31class AnalysisDeclContextManager; 32class ObjCForCollectionStmt; 33 34namespace ento { 35 36class AnalysisManager; 37class CallOrObjCMessage; 38class ObjCMessage; 39 40class ExprEngine : public SubEngine { 41 AnalysisManager &AMgr; 42 43 AnalysisDeclContextManager &AnalysisDeclContexts; 44 45 CoreEngine Engine; 46 47 /// G - the simulation graph. 48 ExplodedGraph& G; 49 50 /// StateMgr - Object that manages the data for all created states. 51 ProgramStateManager StateMgr; 52 53 /// SymMgr - Object that manages the symbol information. 54 SymbolManager& SymMgr; 55 56 /// svalBuilder - SValBuilder object that creates SVals from expressions. 57 SValBuilder &svalBuilder; 58 59 /// EntryNode - The immediate predecessor node. 60 ExplodedNode *EntryNode; 61 62 /// CleanedState - The state for EntryNode "cleaned" of all dead 63 /// variables and symbols (as determined by a liveness analysis). 64 const ProgramState *CleanedState; 65 66 /// currentStmt - The current block-level statement. 67 const Stmt *currentStmt; 68 unsigned int currentStmtIdx; 69 const NodeBuilderContext *currentBuilderContext; 70 71 /// Obj-C Class Identifiers. 72 IdentifierInfo* NSExceptionII; 73 74 /// Obj-C Selectors. 75 Selector* NSExceptionInstanceRaiseSelectors; 76 Selector RaiseSel; 77 78 /// Whether or not GC is enabled in this analysis. 79 bool ObjCGCEnabled; 80 81 /// The BugReporter associated with this engine. It is important that 82 /// this object be placed at the very end of member variables so that its 83 /// destructor is called before the rest of the ExprEngine is destroyed. 84 GRBugReporter BR; 85 86public: 87 ExprEngine(AnalysisManager &mgr, bool gcEnabled); 88 89 ~ExprEngine(); 90 91 void ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) { 92 Engine.ExecuteWorkList(L, Steps, 0); 93 } 94 95 /// Execute the work list with an initial state. Nodes that reaches the exit 96 /// of the function are added into the Dst set, which represent the exit 97 /// state of the function call. 98 void ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps, 99 const ProgramState *InitState, 100 ExplodedNodeSet &Dst) { 101 Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst); 102 } 103 104 /// getContext - Return the ASTContext associated with this analysis. 105 ASTContext &getContext() const { return AMgr.getASTContext(); } 106 107 virtual AnalysisManager &getAnalysisManager() { return AMgr; } 108 109 CheckerManager &getCheckerManager() const { 110 return *AMgr.getCheckerManager(); 111 } 112 113 SValBuilder &getSValBuilder() { return svalBuilder; } 114 115 BugReporter& getBugReporter() { return BR; } 116 117 const NodeBuilderContext &getBuilderContext() { 118 assert(currentBuilderContext); 119 return *currentBuilderContext; 120 } 121 122 bool isObjCGCEnabled() { return ObjCGCEnabled; } 123 124 const Stmt *getStmt() const; 125 126 void GenerateAutoTransition(ExplodedNode *N); 127 128 /// ViewGraph - Visualize the ExplodedGraph created by executing the 129 /// simulation. 130 void ViewGraph(bool trim = false); 131 132 void ViewGraph(ExplodedNode** Beg, ExplodedNode** End); 133 134 /// getInitialState - Return the initial state used for the root vertex 135 /// in the ExplodedGraph. 136 const ProgramState *getInitialState(const LocationContext *InitLoc); 137 138 ExplodedGraph& getGraph() { return G; } 139 const ExplodedGraph& getGraph() const { return G; } 140 141 /// processCFGElement - Called by CoreEngine. Used to generate new successor 142 /// nodes by processing the 'effects' of a CFG element. 143 void processCFGElement(const CFGElement E, ExplodedNode *Pred, 144 unsigned StmtIdx, NodeBuilderContext *Ctx); 145 146 void ProcessStmt(const CFGStmt S, ExplodedNode *Pred); 147 148 void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred); 149 150 void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred); 151 152 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 153 ExplodedNode *Pred, ExplodedNodeSet &Dst); 154 void ProcessBaseDtor(const CFGBaseDtor D, 155 ExplodedNode *Pred, ExplodedNodeSet &Dst); 156 void ProcessMemberDtor(const CFGMemberDtor D, 157 ExplodedNode *Pred, ExplodedNodeSet &Dst); 158 void ProcessTemporaryDtor(const CFGTemporaryDtor D, 159 ExplodedNode *Pred, ExplodedNodeSet &Dst); 160 161 /// Called by CoreEngine when processing the entrance of a CFGBlock. 162 virtual void processCFGBlockEntrance(ExplodedNodeSet &dstNodes, 163 GenericNodeBuilder<BlockEntrance> &nodeBuilder); 164 165 /// ProcessBranch - Called by CoreEngine. Used to generate successor 166 /// nodes by processing the 'effects' of a branch condition. 167 void processBranch(const Stmt *Condition, const Stmt *Term, 168 NodeBuilderContext& BuilderCtx, 169 ExplodedNode *Pred, 170 ExplodedNodeSet &Dst, 171 const CFGBlock *DstT, 172 const CFGBlock *DstF); 173 174 /// processIndirectGoto - Called by CoreEngine. Used to generate successor 175 /// nodes by processing the 'effects' of a computed goto jump. 176 void processIndirectGoto(IndirectGotoNodeBuilder& builder); 177 178 /// ProcessSwitch - Called by CoreEngine. Used to generate successor 179 /// nodes by processing the 'effects' of a switch statement. 180 void processSwitch(SwitchNodeBuilder& builder); 181 182 /// ProcessEndPath - Called by CoreEngine. Used to generate end-of-path 183 /// nodes when the control reaches the end of a function. 184 void processEndOfFunction(EndOfFunctionNodeBuilder& builder); 185 186 /// Generate the entry node of the callee. 187 void processCallEnter(CallEnterNodeBuilder &builder); 188 189 /// Generate the first post callsite node. 190 void processCallExit(CallExitNodeBuilder &builder); 191 192 /// Called by CoreEngine when the analysis worklist has terminated. 193 void processEndWorklist(bool hasWorkRemaining); 194 195 /// evalAssume - Callback function invoked by the ConstraintManager when 196 /// making assumptions about state values. 197 const ProgramState *processAssume(const ProgramState *state, SVal cond,bool assumption); 198 199 /// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a 200 /// region change should trigger a processRegionChanges update. 201 bool wantsRegionChangeUpdate(const ProgramState *state); 202 203 /// processRegionChanges - Called by ProgramStateManager whenever a change is made 204 /// to the store. Used to update checkers that track region values. 205 const ProgramState * 206 processRegionChanges(const ProgramState *state, 207 const StoreManager::InvalidatedSymbols *invalidated, 208 ArrayRef<const MemRegion *> ExplicitRegions, 209 ArrayRef<const MemRegion *> Regions); 210 211 /// printState - Called by ProgramStateManager to print checker-specific data. 212 void printState(raw_ostream &Out, const ProgramState *State, 213 const char *NL, const char *Sep); 214 215 virtual ProgramStateManager& getStateManager() { return StateMgr; } 216 217 StoreManager& getStoreManager() { return StateMgr.getStoreManager(); } 218 219 ConstraintManager& getConstraintManager() { 220 return StateMgr.getConstraintManager(); 221 } 222 223 // FIXME: Remove when we migrate over to just using SValBuilder. 224 BasicValueFactory& getBasicVals() { 225 return StateMgr.getBasicVals(); 226 } 227 const BasicValueFactory& getBasicVals() const { 228 return StateMgr.getBasicVals(); 229 } 230 231 // FIXME: Remove when we migrate over to just using ValueManager. 232 SymbolManager& getSymbolManager() { return SymMgr; } 233 const SymbolManager& getSymbolManager() const { return SymMgr; } 234 235 // Functions for external checking of whether we have unfinished work 236 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); } 237 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); } 238 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); } 239 240 const CoreEngine &getCoreEngine() const { return Engine; } 241 242public: 243 /// Visit - Transfer function logic for all statements. Dispatches to 244 /// other functions that handle specific kinds of statements. 245 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst); 246 247 /// VisitArraySubscriptExpr - Transfer function for array accesses. 248 void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr *Ex, 249 ExplodedNode *Pred, 250 ExplodedNodeSet &Dst); 251 252 /// VisitAsmStmt - Transfer function logic for inline asm. 253 void VisitAsmStmt(const AsmStmt *A, ExplodedNode *Pred, ExplodedNodeSet &Dst); 254 255 void VisitAsmStmtHelperOutputs(const AsmStmt *A, 256 AsmStmt::const_outputs_iterator I, 257 AsmStmt::const_outputs_iterator E, 258 ExplodedNode *Pred, ExplodedNodeSet &Dst); 259 260 void VisitAsmStmtHelperInputs(const AsmStmt *A, 261 AsmStmt::const_inputs_iterator I, 262 AsmStmt::const_inputs_iterator E, 263 ExplodedNode *Pred, ExplodedNodeSet &Dst); 264 265 /// VisitBlockExpr - Transfer function logic for BlockExprs. 266 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 267 ExplodedNodeSet &Dst); 268 269 /// VisitBinaryOperator - Transfer function logic for binary operators. 270 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred, 271 ExplodedNodeSet &Dst); 272 273 274 /// VisitCall - Transfer function for function calls. 275 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 276 ExplodedNodeSet &Dst); 277 278 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 279 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 280 ExplodedNodeSet &Dst); 281 282 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 283 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 284 ExplodedNode *Pred, ExplodedNodeSet &Dst); 285 286 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 287 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D, 288 ExplodedNode *Pred, ExplodedNodeSet &Dst); 289 290 /// VisitDeclStmt - Transfer function logic for DeclStmts. 291 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 292 ExplodedNodeSet &Dst); 293 294 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 295 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R, 296 ExplodedNode *Pred, ExplodedNodeSet &Dst); 297 298 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred, 299 ExplodedNodeSet &Dst); 300 301 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 302 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 303 ExplodedNodeSet &Dst); 304 305 /// VisitMemberExpr - Transfer function for member expressions. 306 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred, 307 ExplodedNodeSet &Dst); 308 309 /// Transfer function logic for ObjCAtSynchronizedStmts. 310 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 311 ExplodedNode *Pred, ExplodedNodeSet &Dst); 312 313 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 314 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred, 315 ExplodedNodeSet &Dst); 316 317 /// VisitObjCForCollectionStmt - Transfer function logic for 318 /// ObjCForCollectionStmt. 319 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S, 320 ExplodedNode *Pred, ExplodedNodeSet &Dst); 321 322 void VisitObjCMessage(const ObjCMessage &msg, ExplodedNode *Pred, 323 ExplodedNodeSet &Dst); 324 325 /// VisitReturnStmt - Transfer function logic for return statements. 326 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred, 327 ExplodedNodeSet &Dst); 328 329 /// VisitOffsetOfExpr - Transfer function for offsetof. 330 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred, 331 ExplodedNodeSet &Dst); 332 333 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 334 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 335 ExplodedNode *Pred, ExplodedNodeSet &Dst); 336 337 /// VisitUnaryOperator - Transfer function logic for unary operators. 338 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred, 339 ExplodedNodeSet &Dst); 340 341 /// Handle ++ and -- (both pre- and post-increment). 342 void VisitIncrementDecrementOperator(const UnaryOperator* U, 343 ExplodedNode *Pred, 344 ExplodedNodeSet &Dst); 345 346 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 347 ExplodedNodeSet & Dst); 348 349 void VisitCXXTemporaryObjectExpr(const CXXTemporaryObjectExpr *expr, 350 ExplodedNode *Pred, ExplodedNodeSet &Dst) { 351 VisitCXXConstructExpr(expr, 0, Pred, Dst); 352 } 353 354 void VisitCXXConstructExpr(const CXXConstructExpr *E, const MemRegion *Dest, 355 ExplodedNode *Pred, ExplodedNodeSet &Dst); 356 357 void VisitCXXDestructor(const CXXDestructorDecl *DD, 358 const MemRegion *Dest, const Stmt *S, 359 ExplodedNode *Pred, ExplodedNodeSet &Dst); 360 361 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 362 ExplodedNodeSet &Dst); 363 364 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 365 ExplodedNodeSet &Dst); 366 367 void VisitAggExpr(const Expr *E, const MemRegion *Dest, ExplodedNode *Pred, 368 ExplodedNodeSet &Dst); 369 370 /// Create a C++ temporary object for an rvalue. 371 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 372 ExplodedNode *Pred, 373 ExplodedNodeSet &Dst); 374 375 /// Synthesize CXXThisRegion. 376 const CXXThisRegion *getCXXThisRegion(const CXXRecordDecl *RD, 377 const StackFrameContext *SFC); 378 379 const CXXThisRegion *getCXXThisRegion(const CXXMethodDecl *decl, 380 const StackFrameContext *frameCtx); 381 382 /// Evaluate arguments with a work list algorithm. 383 void evalArguments(ConstExprIterator AI, ConstExprIterator AE, 384 const FunctionProtoType *FnType, 385 ExplodedNode *Pred, ExplodedNodeSet &Dst, 386 bool FstArgAsLValue = false); 387 388 /// Evaluate callee expression (for a function call). 389 void evalCallee(const CallExpr *callExpr, const ExplodedNodeSet &src, 390 ExplodedNodeSet &dest); 391 392 /// evalEagerlyAssume - Given the nodes in 'Src', eagerly assume symbolic 393 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 394 /// with those assumptions. 395 void evalEagerlyAssume(ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 396 const Expr *Ex); 397 398 std::pair<const ProgramPointTag *, const ProgramPointTag*> 399 getEagerlyAssumeTags(); 400 401 SVal evalMinus(SVal X) { 402 return X.isValid() ? svalBuilder.evalMinus(cast<NonLoc>(X)) : X; 403 } 404 405 SVal evalComplement(SVal X) { 406 return X.isValid() ? svalBuilder.evalComplement(cast<NonLoc>(X)) : X; 407 } 408 409public: 410 411 SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op, 412 NonLoc L, NonLoc R, QualType T) { 413 return svalBuilder.evalBinOpNN(state, op, L, R, T); 414 } 415 416 SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op, 417 NonLoc L, SVal R, QualType T) { 418 return R.isValid() ? svalBuilder.evalBinOpNN(state,op,L, cast<NonLoc>(R), T) : R; 419 } 420 421 SVal evalBinOp(const ProgramState *ST, BinaryOperator::Opcode Op, 422 SVal LHS, SVal RHS, QualType T) { 423 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 424 } 425 426protected: 427 void evalObjCMessage(PureStmtNodeBuilder &Bldr, const ObjCMessage &msg, 428 ExplodedNode *Pred, const ProgramState *state, 429 bool GenSink); 430 431 const ProgramState *invalidateArguments(const ProgramState *State, 432 const CallOrObjCMessage &Call, 433 const LocationContext *LC); 434 435 const ProgramState *MarkBranch(const ProgramState *St, const Stmt *Terminator, 436 bool branchTaken); 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 ProgramPoint::Kind PP = ProgramPoint::PostStmtKind); 443 444public: 445 // FIXME: 'tag' should be removed, and a LocationContext should be used 446 // instead. 447 // FIXME: Comment on the meaning of the arguments, when 'St' may not 448 // be the same as Pred->state, and when 'location' may not be the 449 // same as state->getLValue(Ex). 450 /// Simulate a read of the result of Ex. 451 void evalLoad(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred, 452 const ProgramState *St, SVal location, const ProgramPointTag *tag = 0, 453 QualType LoadTy = QualType()); 454 455 // FIXME: 'tag' should be removed, and a LocationContext should be used 456 // instead. 457 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE, 458 ExplodedNode *Pred, const ProgramState *St, SVal TargetLV, SVal Val, 459 const ProgramPointTag *tag = 0); 460private: 461 void evalLoadCommon(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred, 462 const ProgramState *St, SVal location, const ProgramPointTag *tag, 463 QualType LoadTy); 464 465 // FIXME: 'tag' should be removed, and a LocationContext should be used 466 // instead. 467 void evalLocation(ExplodedNodeSet &Dst, const Stmt *S, ExplodedNode *Pred, 468 const ProgramState *St, SVal location, 469 const ProgramPointTag *tag, bool isLoad); 470 471 bool InlineCall(ExplodedNodeSet &Dst, const CallExpr *CE, ExplodedNode *Pred); 472 473 474public: 475 /// Returns true if calling the specific function or method would possibly 476 /// cause global variables to be invalidated. 477 bool doesInvalidateGlobals(const CallOrObjCMessage &callOrMessage) const; 478 479}; 480 481} // end ento namespace 482 483} // end clang namespace 484 485#endif 486