ExprEngine.h revision 35bdbf40624beba3fc00cb72ab444659939c1a6b
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/GRState.h" 23#include "clang/StaticAnalyzer/Core/PathSensitive/TransferFuncs.h" 24#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 25#include "clang/AST/Type.h" 26#include "clang/AST/ExprObjC.h" 27#include "clang/AST/ExprCXX.h" 28#include "clang/AST/StmtObjC.h" 29 30namespace clang { 31 32class ObjCForCollectionStmt; 33 34namespace ento { 35 36class AnalysisManager; 37 38class ExprEngine : public SubEngine { 39 AnalysisManager &AMgr; 40 41 CoreEngine Engine; 42 43 /// G - the simulation graph. 44 ExplodedGraph& G; 45 46 /// Builder - The current StmtNodeBuilder which is used when building the 47 /// nodes for a given statement. 48 StmtNodeBuilder* Builder; 49 50 /// StateMgr - Object that manages the data for all created states. 51 GRStateManager 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 GRState* CleanedState; 65 66 /// currentStmt - The current block-level statement. 67 const Stmt* currentStmt; 68 69 // Obj-C Class Identifiers. 70 IdentifierInfo* NSExceptionII; 71 72 // Obj-C Selectors. 73 Selector* NSExceptionInstanceRaiseSelectors; 74 Selector RaiseSel; 75 76 /// The BugReporter associated with this engine. It is important that 77 /// this object be placed at the very end of member variables so that its 78 /// destructor is called before the rest of the ExprEngine is destroyed. 79 GRBugReporter BR; 80 81 llvm::OwningPtr<TransferFuncs> TF; 82 83public: 84 ExprEngine(AnalysisManager &mgr, TransferFuncs *tf); 85 86 ~ExprEngine(); 87 88 void ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) { 89 Engine.ExecuteWorkList(L, Steps, 0); 90 } 91 92 /// Execute the work list with an initial state. Nodes that reaches the exit 93 /// of the function are added into the Dst set, which represent the exit 94 /// state of the function call. 95 void ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps, 96 const GRState *InitState, 97 ExplodedNodeSet &Dst) { 98 Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst); 99 } 100 101 /// getContext - Return the ASTContext associated with this analysis. 102 ASTContext& getContext() const { return AMgr.getASTContext(); } 103 104 virtual AnalysisManager &getAnalysisManager() { return AMgr; } 105 106 CheckerManager &getCheckerManager() const { 107 return *AMgr.getCheckerManager(); 108 } 109 110 SValBuilder &getSValBuilder() { return svalBuilder; } 111 112 TransferFuncs& getTF() { return *TF; } 113 114 BugReporter& getBugReporter() { return BR; } 115 116 StmtNodeBuilder &getBuilder() { assert(Builder); return *Builder; } 117 118 // FIXME: Remove once TransferFuncs is no longer referenced. 119 void setTransferFunction(TransferFuncs* tf); 120 121 /// ViewGraph - Visualize the ExplodedGraph created by executing the 122 /// simulation. 123 void ViewGraph(bool trim = false); 124 125 void ViewGraph(ExplodedNode** Beg, ExplodedNode** End); 126 127 /// getInitialState - Return the initial state used for the root vertex 128 /// in the ExplodedGraph. 129 const GRState* getInitialState(const LocationContext *InitLoc); 130 131 ExplodedGraph& getGraph() { return G; } 132 const ExplodedGraph& getGraph() const { return G; } 133 134 /// processCFGElement - Called by CoreEngine. Used to generate new successor 135 /// nodes by processing the 'effects' of a CFG element. 136 void processCFGElement(const CFGElement E, StmtNodeBuilder& builder); 137 138 void ProcessStmt(const CFGStmt S, StmtNodeBuilder &builder); 139 140 void ProcessInitializer(const CFGInitializer I, StmtNodeBuilder &builder); 141 142 void ProcessImplicitDtor(const CFGImplicitDtor D, StmtNodeBuilder &builder); 143 144 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 145 StmtNodeBuilder &builder); 146 void ProcessBaseDtor(const CFGBaseDtor D, StmtNodeBuilder &builder); 147 void ProcessMemberDtor(const CFGMemberDtor D, StmtNodeBuilder &builder); 148 void ProcessTemporaryDtor(const CFGTemporaryDtor D, 149 StmtNodeBuilder &builder); 150 151 /// Called by CoreEngine when processing the entrance of a CFGBlock. 152 virtual void processCFGBlockEntrance(ExplodedNodeSet &dstNodes, 153 GenericNodeBuilder<BlockEntrance> &nodeBuilder); 154 155 /// ProcessBranch - Called by CoreEngine. Used to generate successor 156 /// nodes by processing the 'effects' of a branch condition. 157 void processBranch(const Stmt* Condition, const Stmt* Term, 158 BranchNodeBuilder& builder); 159 160 /// processIndirectGoto - Called by CoreEngine. Used to generate successor 161 /// nodes by processing the 'effects' of a computed goto jump. 162 void processIndirectGoto(IndirectGotoNodeBuilder& builder); 163 164 /// ProcessSwitch - Called by CoreEngine. Used to generate successor 165 /// nodes by processing the 'effects' of a switch statement. 166 void processSwitch(SwitchNodeBuilder& builder); 167 168 /// ProcessEndPath - Called by CoreEngine. Used to generate end-of-path 169 /// nodes when the control reaches the end of a function. 170 void processEndOfFunction(EndOfFunctionNodeBuilder& builder); 171 172 /// Generate the entry node of the callee. 173 void processCallEnter(CallEnterNodeBuilder &builder); 174 175 /// Generate the first post callsite node. 176 void processCallExit(CallExitNodeBuilder &builder); 177 178 /// Called by CoreEngine when the analysis worklist has terminated. 179 void processEndWorklist(bool hasWorkRemaining); 180 181 /// evalAssume - Callback function invoked by the ConstraintManager when 182 /// making assumptions about state values. 183 const GRState *processAssume(const GRState *state, SVal cond,bool assumption); 184 185 /// wantsRegionChangeUpdate - Called by GRStateManager to determine if a 186 /// region change should trigger a processRegionChanges update. 187 bool wantsRegionChangeUpdate(const GRState* state); 188 189 /// processRegionChanges - Called by GRStateManager whenever a change is made 190 /// to the store. Used to update checkers that track region values. 191 const GRState * 192 processRegionChanges(const GRState *state, 193 const StoreManager::InvalidatedSymbols *invalidated, 194 const MemRegion * const *Begin, 195 const MemRegion * const *End); 196 197 virtual GRStateManager& getStateManager() { return StateMgr; } 198 199 StoreManager& getStoreManager() { return StateMgr.getStoreManager(); } 200 201 ConstraintManager& getConstraintManager() { 202 return StateMgr.getConstraintManager(); 203 } 204 205 // FIXME: Remove when we migrate over to just using SValBuilder. 206 BasicValueFactory& getBasicVals() { 207 return StateMgr.getBasicVals(); 208 } 209 const BasicValueFactory& getBasicVals() const { 210 return StateMgr.getBasicVals(); 211 } 212 213 // FIXME: Remove when we migrate over to just using ValueManager. 214 SymbolManager& getSymbolManager() { return SymMgr; } 215 const SymbolManager& getSymbolManager() const { return SymMgr; } 216 217 // Functions for external checking of whether we have unfinished work 218 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); } 219 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); } 220 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); } 221 222 const CoreEngine &getCoreEngine() const { return Engine; } 223 224protected: 225 const GRState* GetState(ExplodedNode* N) { 226 return N == EntryNode ? CleanedState : N->getState(); 227 } 228 229public: 230 ExplodedNode* MakeNode(ExplodedNodeSet& Dst, const Stmt* S, 231 ExplodedNode* Pred, const GRState* St, 232 ProgramPoint::Kind K = ProgramPoint::PostStmtKind, 233 const void *tag = 0); 234 235 /// Visit - Transfer function logic for all statements. Dispatches to 236 /// other functions that handle specific kinds of statements. 237 void Visit(const Stmt* S, ExplodedNode* Pred, ExplodedNodeSet& Dst); 238 239 /// VisitArraySubscriptExpr - Transfer function for array accesses. 240 void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr* Ex, 241 ExplodedNode* Pred, 242 ExplodedNodeSet& Dst); 243 244 /// VisitAsmStmt - Transfer function logic for inline asm. 245 void VisitAsmStmt(const AsmStmt* A, ExplodedNode* Pred, ExplodedNodeSet& Dst); 246 247 void VisitAsmStmtHelperOutputs(const AsmStmt* A, 248 AsmStmt::const_outputs_iterator I, 249 AsmStmt::const_outputs_iterator E, 250 ExplodedNode* Pred, ExplodedNodeSet& Dst); 251 252 void VisitAsmStmtHelperInputs(const AsmStmt* A, 253 AsmStmt::const_inputs_iterator I, 254 AsmStmt::const_inputs_iterator E, 255 ExplodedNode* Pred, ExplodedNodeSet& Dst); 256 257 /// VisitBlockExpr - Transfer function logic for BlockExprs. 258 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 259 ExplodedNodeSet &Dst); 260 261 /// VisitBinaryOperator - Transfer function logic for binary operators. 262 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode* Pred, 263 ExplodedNodeSet& Dst); 264 265 266 /// VisitCall - Transfer function for function calls. 267 void VisitCallExpr(const CallExpr* CE, ExplodedNode* Pred, 268 ExplodedNodeSet& Dst); 269 270 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 271 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 272 ExplodedNodeSet &Dst); 273 274 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 275 void VisitCompoundLiteralExpr(const CompoundLiteralExpr* CL, 276 ExplodedNode* Pred, ExplodedNodeSet& Dst); 277 278 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 279 void VisitCommonDeclRefExpr(const Expr* DR, const NamedDecl *D, 280 ExplodedNode* Pred, ExplodedNodeSet& Dst); 281 282 /// VisitDeclStmt - Transfer function logic for DeclStmts. 283 void VisitDeclStmt(const DeclStmt* DS, ExplodedNode* Pred, 284 ExplodedNodeSet& Dst); 285 286 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 287 void VisitGuardedExpr(const Expr* Ex, const Expr* L, const Expr* R, 288 ExplodedNode* Pred, ExplodedNodeSet& Dst); 289 290 void VisitInitListExpr(const InitListExpr* E, ExplodedNode* Pred, 291 ExplodedNodeSet& Dst); 292 293 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 294 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode* Pred, 295 ExplodedNodeSet& Dst); 296 297 /// VisitMemberExpr - Transfer function for member expressions. 298 void VisitMemberExpr(const MemberExpr* M, ExplodedNode* Pred, 299 ExplodedNodeSet& Dst); 300 301 /// Transfer function logic for ObjCAtSynchronizedStmts. 302 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 303 ExplodedNode *Pred, ExplodedNodeSet &Dst); 304 305 void VisitObjCPropertyRefExpr(const ObjCPropertyRefExpr *E, 306 ExplodedNode *Pred, ExplodedNodeSet &Dst); 307 308 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 309 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr* DR, ExplodedNode* Pred, 310 ExplodedNodeSet& Dst); 311 312 /// VisitObjCForCollectionStmt - Transfer function logic for 313 /// ObjCForCollectionStmt. 314 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt* S, 315 ExplodedNode* Pred, ExplodedNodeSet& Dst); 316 317 void VisitObjCForCollectionStmtAux(const ObjCForCollectionStmt* S, 318 ExplodedNode* Pred, 319 ExplodedNodeSet& Dst, SVal ElementV); 320 321 /// VisitObjCMessageExpr - Transfer function for ObjC message expressions. 322 void VisitObjCMessageExpr(const ObjCMessageExpr* ME, ExplodedNode* Pred, 323 ExplodedNodeSet& Dst); 324 void VisitObjCMessage(const ObjCMessage &msg, ExplodedNodeSet &Src, 325 ExplodedNodeSet& Dst); 326 327 /// VisitReturnStmt - Transfer function logic for return statements. 328 void VisitReturnStmt(const ReturnStmt* R, ExplodedNode* Pred, 329 ExplodedNodeSet& Dst); 330 331 /// VisitOffsetOfExpr - Transfer function for offsetof. 332 void VisitOffsetOfExpr(const OffsetOfExpr* Ex, ExplodedNode* Pred, 333 ExplodedNodeSet& Dst); 334 335 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 336 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr* Ex, 337 ExplodedNode* Pred, ExplodedNodeSet& Dst); 338 339 /// VisitUnaryOperator - Transfer function logic for unary operators. 340 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode* Pred, 341 ExplodedNodeSet& Dst); 342 343 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 344 ExplodedNodeSet & Dst); 345 346 void VisitCXXTemporaryObjectExpr(const CXXTemporaryObjectExpr *expr, 347 ExplodedNode *Pred, ExplodedNodeSet &Dst) { 348 VisitCXXConstructExpr(expr, 0, Pred, Dst); 349 } 350 351 void VisitCXXConstructExpr(const CXXConstructExpr *E, const MemRegion *Dest, 352 ExplodedNode *Pred, ExplodedNodeSet &Dst); 353 354 void VisitCXXDestructor(const CXXDestructorDecl *DD, 355 const MemRegion *Dest, const Stmt *S, 356 ExplodedNode *Pred, ExplodedNodeSet &Dst); 357 358 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 359 ExplodedNodeSet &Dst); 360 361 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 362 ExplodedNodeSet &Dst); 363 364 void VisitAggExpr(const Expr *E, const MemRegion *Dest, ExplodedNode *Pred, 365 ExplodedNodeSet &Dst); 366 367 /// Create a C++ temporary object for an rvalue. 368 void CreateCXXTemporaryObject(const Expr *Ex, ExplodedNode *Pred, 369 ExplodedNodeSet &Dst); 370 371 /// Synthesize CXXThisRegion. 372 const CXXThisRegion *getCXXThisRegion(const CXXRecordDecl *RD, 373 const StackFrameContext *SFC); 374 375 const CXXThisRegion *getCXXThisRegion(const CXXMethodDecl *decl, 376 const StackFrameContext *frameCtx); 377 378 /// Evaluate arguments with a work list algorithm. 379 void evalArguments(ConstExprIterator AI, ConstExprIterator AE, 380 const FunctionProtoType *FnType, 381 ExplodedNode *Pred, ExplodedNodeSet &Dst, 382 bool FstArgAsLValue = false); 383 384 /// Evaluate callee expression (for a function call). 385 void evalCallee(const CallExpr *callExpr, const ExplodedNodeSet &src, 386 ExplodedNodeSet &dest); 387 388 /// evalEagerlyAssume - Given the nodes in 'Src', eagerly assume symbolic 389 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 390 /// with those assumptions. 391 void evalEagerlyAssume(ExplodedNodeSet& Dst, ExplodedNodeSet& Src, 392 const Expr *Ex); 393 394 SVal evalMinus(SVal X) { 395 return X.isValid() ? svalBuilder.evalMinus(cast<NonLoc>(X)) : X; 396 } 397 398 SVal evalComplement(SVal X) { 399 return X.isValid() ? svalBuilder.evalComplement(cast<NonLoc>(X)) : X; 400 } 401 402public: 403 404 SVal evalBinOp(const GRState *state, BinaryOperator::Opcode op, 405 NonLoc L, NonLoc R, QualType T) { 406 return svalBuilder.evalBinOpNN(state, op, L, R, T); 407 } 408 409 SVal evalBinOp(const GRState *state, BinaryOperator::Opcode op, 410 NonLoc L, SVal R, QualType T) { 411 return R.isValid() ? svalBuilder.evalBinOpNN(state,op,L, cast<NonLoc>(R), T) : R; 412 } 413 414 SVal evalBinOp(const GRState *ST, BinaryOperator::Opcode Op, 415 SVal LHS, SVal RHS, QualType T) { 416 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 417 } 418 419protected: 420 void evalObjCMessage(ExplodedNodeSet& Dst, const ObjCMessage &msg, 421 ExplodedNode* Pred, const GRState *state) { 422 assert (Builder && "StmtNodeBuilder must be defined."); 423 getTF().evalObjCMessage(Dst, *this, *Builder, msg, Pred, state); 424 } 425 426 const GRState* MarkBranch(const GRState* 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 const GRState* St, SVal location, SVal Val, 433 bool atDeclInit = false); 434 435public: 436 // FIXME: 'tag' should be removed, and a LocationContext should be used 437 // instead. 438 // FIXME: Comment on the meaning of the arguments, when 'St' may not 439 // be the same as Pred->state, and when 'location' may not be the 440 // same as state->getLValue(Ex). 441 /// Simulate a read of the result of Ex. 442 void evalLoad(ExplodedNodeSet& Dst, const Expr* Ex, ExplodedNode* Pred, 443 const GRState* St, SVal location, const void *tag = 0, 444 QualType LoadTy = QualType()); 445 446 // FIXME: 'tag' should be removed, and a LocationContext should be used 447 // instead. 448 void evalStore(ExplodedNodeSet& Dst, const Expr* AssignE, const Expr* StoreE, 449 ExplodedNode* Pred, const GRState* St, SVal TargetLV, SVal Val, 450 const void *tag = 0); 451private: 452 void evalLoadCommon(ExplodedNodeSet& Dst, const Expr* Ex, ExplodedNode* Pred, 453 const GRState* St, SVal location, const void *tag, 454 QualType LoadTy); 455 456 // FIXME: 'tag' should be removed, and a LocationContext should be used 457 // instead. 458 void evalLocation(ExplodedNodeSet &Dst, const Stmt *S, ExplodedNode* Pred, 459 const GRState* St, SVal location, 460 const void *tag, bool isLoad); 461 462 bool InlineCall(ExplodedNodeSet &Dst, const CallExpr *CE, ExplodedNode *Pred); 463}; 464 465} // end ento namespace 466 467} // end clang namespace 468 469#endif 470