ExprEngine.h revision 70a34da7a767bda69958d8f659de9f87b03de747
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/PathSensitive/ObjCMessage.h" 25#include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h" 26#include "clang/AST/Type.h" 27#include "clang/AST/ExprObjC.h" 28#include "clang/AST/ExprCXX.h" 29#include "clang/AST/StmtObjC.h" 30 31namespace clang { 32 33class ObjCForCollectionStmt; 34 35namespace ento { 36 37class AnalysisManager; 38 39class 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 GRStateManager 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 GRState* 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 /// The BugReporter associated with this engine. It is important that 78 /// this object be placed at the very end of member variables so that its 79 /// destructor is called before the rest of the ExprEngine is destroyed. 80 GRBugReporter BR; 81 82 llvm::OwningPtr<TransferFuncs> TF; 83 84public: 85 ExprEngine(AnalysisManager &mgr, TransferFuncs *tf); 86 87 ~ExprEngine(); 88 89 void ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) { 90 Engine.ExecuteWorkList(L, Steps, 0); 91 } 92 93 /// Execute the work list with an initial state. Nodes that reaches the exit 94 /// of the function are added into the Dst set, which represent the exit 95 /// state of the function call. 96 void ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps, 97 const GRState *InitState, 98 ExplodedNodeSet &Dst) { 99 Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst); 100 } 101 102 /// getContext - Return the ASTContext associated with this analysis. 103 ASTContext& getContext() const { return AMgr.getASTContext(); } 104 105 virtual AnalysisManager &getAnalysisManager() { return AMgr; } 106 107 CheckerManager &getCheckerManager() const { 108 return *AMgr.getCheckerManager(); 109 } 110 111 SValBuilder &getSValBuilder() { return svalBuilder; } 112 113 TransferFuncs& getTF() { return *TF; } 114 115 BugReporter& getBugReporter() { return BR; } 116 117 StmtNodeBuilder &getBuilder() { assert(Builder); return *Builder; } 118 119 // FIXME: Remove once TransferFuncs is no longer referenced. 120 void setTransferFunction(TransferFuncs* tf); 121 122 /// ViewGraph - Visualize the ExplodedGraph created by executing the 123 /// simulation. 124 void ViewGraph(bool trim = false); 125 126 void ViewGraph(ExplodedNode** Beg, ExplodedNode** End); 127 128 /// getInitialState - Return the initial state used for the root vertex 129 /// in the ExplodedGraph. 130 const GRState* getInitialState(const LocationContext *InitLoc); 131 132 ExplodedGraph& getGraph() { return G; } 133 const ExplodedGraph& getGraph() const { return G; } 134 135 /// processCFGElement - Called by CoreEngine. Used to generate new successor 136 /// nodes by processing the 'effects' of a CFG element. 137 void processCFGElement(const CFGElement E, StmtNodeBuilder& builder); 138 139 void ProcessStmt(const CFGStmt S, StmtNodeBuilder &builder); 140 141 void ProcessInitializer(const CFGInitializer I, StmtNodeBuilder &builder); 142 143 void ProcessImplicitDtor(const CFGImplicitDtor D, StmtNodeBuilder &builder); 144 145 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 146 StmtNodeBuilder &builder); 147 void ProcessBaseDtor(const CFGBaseDtor D, StmtNodeBuilder &builder); 148 void ProcessMemberDtor(const CFGMemberDtor D, StmtNodeBuilder &builder); 149 void ProcessTemporaryDtor(const CFGTemporaryDtor D, 150 StmtNodeBuilder &builder); 151 152 /// Called by CoreEngine when processing the entrance of a CFGBlock. 153 virtual void processCFGBlockEntrance(ExplodedNodeSet &dstNodes, 154 GenericNodeBuilder<BlockEntrance> &nodeBuilder); 155 156 /// ProcessBranch - Called by CoreEngine. Used to generate successor 157 /// nodes by processing the 'effects' of a branch condition. 158 void processBranch(const Stmt* Condition, const Stmt* Term, 159 BranchNodeBuilder& builder); 160 161 /// processIndirectGoto - Called by CoreEngine. Used to generate successor 162 /// nodes by processing the 'effects' of a computed goto jump. 163 void processIndirectGoto(IndirectGotoNodeBuilder& builder); 164 165 /// ProcessSwitch - Called by CoreEngine. Used to generate successor 166 /// nodes by processing the 'effects' of a switch statement. 167 void processSwitch(SwitchNodeBuilder& builder); 168 169 /// ProcessEndPath - Called by CoreEngine. Used to generate end-of-path 170 /// nodes when the control reaches the end of a function. 171 void processEndOfFunction(EndOfFunctionNodeBuilder& builder); 172 173 /// Generate the entry node of the callee. 174 void processCallEnter(CallEnterNodeBuilder &builder); 175 176 /// Generate the first post callsite node. 177 void processCallExit(CallExitNodeBuilder &builder); 178 179 /// Called by CoreEngine when the analysis worklist has terminated. 180 void processEndWorklist(bool hasWorkRemaining); 181 182 /// evalAssume - Callback function invoked by the ConstraintManager when 183 /// making assumptions about state values. 184 const GRState *processAssume(const GRState *state, SVal cond,bool assumption); 185 186 /// wantsRegionChangeUpdate - Called by GRStateManager to determine if a 187 /// region change should trigger a processRegionChanges update. 188 bool wantsRegionChangeUpdate(const GRState* state); 189 190 /// processRegionChanges - Called by GRStateManager whenever a change is made 191 /// to the store. Used to update checkers that track region values. 192 const GRState * 193 processRegionChanges(const GRState *state, 194 const StoreManager::InvalidatedSymbols *invalidated, 195 const MemRegion * const *Begin, 196 const MemRegion * const *End); 197 198 virtual GRStateManager& getStateManager() { return StateMgr; } 199 200 StoreManager& getStoreManager() { return StateMgr.getStoreManager(); } 201 202 ConstraintManager& getConstraintManager() { 203 return StateMgr.getConstraintManager(); 204 } 205 206 // FIXME: Remove when we migrate over to just using SValBuilder. 207 BasicValueFactory& getBasicVals() { 208 return StateMgr.getBasicVals(); 209 } 210 const BasicValueFactory& getBasicVals() const { 211 return StateMgr.getBasicVals(); 212 } 213 214 // FIXME: Remove when we migrate over to just using ValueManager. 215 SymbolManager& getSymbolManager() { return SymMgr; } 216 const SymbolManager& getSymbolManager() const { return SymMgr; } 217 218 // Functions for external checking of whether we have unfinished work 219 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); } 220 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); } 221 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); } 222 223 const CoreEngine &getCoreEngine() const { return Engine; } 224 225protected: 226 const GRState* GetState(ExplodedNode* N) { 227 return N == EntryNode ? CleanedState : N->getState(); 228 } 229 230public: 231 ExplodedNode* MakeNode(ExplodedNodeSet& Dst, const Stmt* S, 232 ExplodedNode* Pred, const GRState* St, 233 ProgramPoint::Kind K = ProgramPoint::PostStmtKind, 234 const void *tag = 0); 235 236 /// Visit - Transfer function logic for all statements. Dispatches to 237 /// other functions that handle specific kinds of statements. 238 void Visit(const Stmt* S, ExplodedNode* Pred, ExplodedNodeSet& Dst); 239 240 /// VisitArraySubscriptExpr - Transfer function for array accesses. 241 void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr* Ex, 242 ExplodedNode* Pred, 243 ExplodedNodeSet& Dst); 244 245 /// VisitAsmStmt - Transfer function logic for inline asm. 246 void VisitAsmStmt(const AsmStmt* A, ExplodedNode* Pred, ExplodedNodeSet& Dst); 247 248 void VisitAsmStmtHelperOutputs(const AsmStmt* A, 249 AsmStmt::const_outputs_iterator I, 250 AsmStmt::const_outputs_iterator E, 251 ExplodedNode* Pred, ExplodedNodeSet& Dst); 252 253 void VisitAsmStmtHelperInputs(const AsmStmt* A, 254 AsmStmt::const_inputs_iterator I, 255 AsmStmt::const_inputs_iterator E, 256 ExplodedNode* Pred, ExplodedNodeSet& Dst); 257 258 /// VisitBlockExpr - Transfer function logic for BlockExprs. 259 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 260 ExplodedNodeSet &Dst); 261 262 /// VisitBinaryOperator - Transfer function logic for binary operators. 263 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode* Pred, 264 ExplodedNodeSet& Dst); 265 266 267 /// VisitCall - Transfer function for function calls. 268 void VisitCallExpr(const CallExpr* CE, ExplodedNode* Pred, 269 ExplodedNodeSet& Dst); 270 271 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 272 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 273 ExplodedNodeSet &Dst); 274 275 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 276 void VisitCompoundLiteralExpr(const CompoundLiteralExpr* CL, 277 ExplodedNode* Pred, ExplodedNodeSet& Dst); 278 279 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 280 void VisitCommonDeclRefExpr(const Expr* DR, const NamedDecl *D, 281 ExplodedNode* Pred, ExplodedNodeSet& Dst); 282 283 /// VisitDeclStmt - Transfer function logic for DeclStmts. 284 void VisitDeclStmt(const DeclStmt* DS, ExplodedNode* Pred, 285 ExplodedNodeSet& Dst); 286 287 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 288 void VisitGuardedExpr(const Expr* Ex, const Expr* L, const Expr* R, 289 ExplodedNode* Pred, ExplodedNodeSet& Dst); 290 291 void VisitInitListExpr(const InitListExpr* E, ExplodedNode* Pred, 292 ExplodedNodeSet& Dst); 293 294 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 295 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode* Pred, 296 ExplodedNodeSet& Dst); 297 298 /// VisitMemberExpr - Transfer function for member expressions. 299 void VisitMemberExpr(const MemberExpr* M, ExplodedNode* Pred, 300 ExplodedNodeSet& Dst); 301 302 /// Transfer function logic for ObjCAtSynchronizedStmts. 303 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 304 ExplodedNode *Pred, ExplodedNodeSet &Dst); 305 306 void VisitObjCPropertyRefExpr(const ObjCPropertyRefExpr *E, 307 ExplodedNode *Pred, ExplodedNodeSet &Dst); 308 309 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 310 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr* DR, ExplodedNode* Pred, 311 ExplodedNodeSet& Dst); 312 313 /// VisitObjCForCollectionStmt - Transfer function logic for 314 /// ObjCForCollectionStmt. 315 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt* S, 316 ExplodedNode* Pred, ExplodedNodeSet& Dst); 317 318 void VisitObjCMessage(const ObjCMessage &msg, ExplodedNode *Pred, 319 ExplodedNodeSet& Dst); 320 321 /// VisitReturnStmt - Transfer function logic for return statements. 322 void VisitReturnStmt(const ReturnStmt* R, ExplodedNode* Pred, 323 ExplodedNodeSet& Dst); 324 325 /// VisitOffsetOfExpr - Transfer function for offsetof. 326 void VisitOffsetOfExpr(const OffsetOfExpr* Ex, ExplodedNode* Pred, 327 ExplodedNodeSet& Dst); 328 329 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 330 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr* Ex, 331 ExplodedNode* Pred, ExplodedNodeSet& Dst); 332 333 /// VisitUnaryOperator - Transfer function logic for unary operators. 334 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode* Pred, 335 ExplodedNodeSet& Dst); 336 337 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 338 ExplodedNodeSet & Dst); 339 340 void VisitCXXTemporaryObjectExpr(const CXXTemporaryObjectExpr *expr, 341 ExplodedNode *Pred, ExplodedNodeSet &Dst) { 342 VisitCXXConstructExpr(expr, 0, Pred, Dst); 343 } 344 345 void VisitCXXConstructExpr(const CXXConstructExpr *E, const MemRegion *Dest, 346 ExplodedNode *Pred, ExplodedNodeSet &Dst); 347 348 void VisitCXXDestructor(const CXXDestructorDecl *DD, 349 const MemRegion *Dest, const Stmt *S, 350 ExplodedNode *Pred, ExplodedNodeSet &Dst); 351 352 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 353 ExplodedNodeSet &Dst); 354 355 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 356 ExplodedNodeSet &Dst); 357 358 void VisitAggExpr(const Expr *E, const MemRegion *Dest, ExplodedNode *Pred, 359 ExplodedNodeSet &Dst); 360 361 /// Create a C++ temporary object for an rvalue. 362 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 363 ExplodedNode *Pred, 364 ExplodedNodeSet &Dst); 365 366 /// Synthesize CXXThisRegion. 367 const CXXThisRegion *getCXXThisRegion(const CXXRecordDecl *RD, 368 const StackFrameContext *SFC); 369 370 const CXXThisRegion *getCXXThisRegion(const CXXMethodDecl *decl, 371 const StackFrameContext *frameCtx); 372 373 /// Evaluate arguments with a work list algorithm. 374 void evalArguments(ConstExprIterator AI, ConstExprIterator AE, 375 const FunctionProtoType *FnType, 376 ExplodedNode *Pred, ExplodedNodeSet &Dst, 377 bool FstArgAsLValue = false); 378 379 /// Evaluate callee expression (for a function call). 380 void evalCallee(const CallExpr *callExpr, const ExplodedNodeSet &src, 381 ExplodedNodeSet &dest); 382 383 /// evalEagerlyAssume - Given the nodes in 'Src', eagerly assume symbolic 384 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 385 /// with those assumptions. 386 void evalEagerlyAssume(ExplodedNodeSet& Dst, ExplodedNodeSet& Src, 387 const Expr *Ex); 388 389 SVal evalMinus(SVal X) { 390 return X.isValid() ? svalBuilder.evalMinus(cast<NonLoc>(X)) : X; 391 } 392 393 SVal evalComplement(SVal X) { 394 return X.isValid() ? svalBuilder.evalComplement(cast<NonLoc>(X)) : X; 395 } 396 397public: 398 399 SVal evalBinOp(const GRState *state, BinaryOperator::Opcode op, 400 NonLoc L, NonLoc R, QualType T) { 401 return svalBuilder.evalBinOpNN(state, op, L, R, T); 402 } 403 404 SVal evalBinOp(const GRState *state, BinaryOperator::Opcode op, 405 NonLoc L, SVal R, QualType T) { 406 return R.isValid() ? svalBuilder.evalBinOpNN(state,op,L, cast<NonLoc>(R), T) : R; 407 } 408 409 SVal evalBinOp(const GRState *ST, BinaryOperator::Opcode Op, 410 SVal LHS, SVal RHS, QualType T) { 411 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 412 } 413 414protected: 415 void evalObjCMessage(ExplodedNodeSet& Dst, const ObjCMessage &msg, 416 ExplodedNode* Pred, const GRState *state) { 417 assert (Builder && "StmtNodeBuilder must be defined."); 418 getTF().evalObjCMessage(Dst, *this, *Builder, msg, Pred, state); 419 } 420 421 const GRState* MarkBranch(const GRState* St, const Stmt* Terminator, 422 bool branchTaken); 423 424 /// evalBind - Handle the semantics of binding a value to a specific location. 425 /// This method is used by evalStore, VisitDeclStmt, and others. 426 void evalBind(ExplodedNodeSet& Dst, const Stmt* StoreE, ExplodedNode* Pred, 427 const GRState* St, SVal location, SVal Val, 428 bool atDeclInit = false); 429 430public: 431 // FIXME: 'tag' should be removed, and a LocationContext should be used 432 // instead. 433 // FIXME: Comment on the meaning of the arguments, when 'St' may not 434 // be the same as Pred->state, and when 'location' may not be the 435 // same as state->getLValue(Ex). 436 /// Simulate a read of the result of Ex. 437 void evalLoad(ExplodedNodeSet& Dst, const Expr* Ex, ExplodedNode* Pred, 438 const GRState* St, SVal location, const void *tag = 0, 439 QualType LoadTy = QualType()); 440 441 // FIXME: 'tag' should be removed, and a LocationContext should be used 442 // instead. 443 void evalStore(ExplodedNodeSet& Dst, const Expr* AssignE, const Expr* StoreE, 444 ExplodedNode* Pred, const GRState* St, SVal TargetLV, SVal Val, 445 const void *tag = 0); 446private: 447 void evalLoadCommon(ExplodedNodeSet& Dst, const Expr* Ex, ExplodedNode* Pred, 448 const GRState* St, SVal location, const void *tag, 449 QualType LoadTy); 450 451 // FIXME: 'tag' should be removed, and a LocationContext should be used 452 // instead. 453 void evalLocation(ExplodedNodeSet &Dst, const Stmt *S, ExplodedNode* Pred, 454 const GRState* St, SVal location, 455 const void *tag, bool isLoad); 456 457 bool InlineCall(ExplodedNodeSet &Dst, const CallExpr *CE, ExplodedNode *Pred); 458 459 460public: 461 /// Returns true if calling the specific function or method would possibly 462 /// cause global variables to be invalidated. 463 bool doesInvalidateGlobals(const CallOrObjCMessage &callOrMessage) const; 464 465}; 466 467} // end ento namespace 468 469} // end clang namespace 470 471#endif 472