ExprEngine.h revision ebae6d0209e1ec3d5ea14f9e63bd0d740218ed14
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 /// Builder - The current StmtNodeBuilder which is used when building the 51 /// nodes for a given statement. 52 StmtNodeBuilder* Builder; 53 54 /// StateMgr - Object that manages the data for all created states. 55 ProgramStateManager StateMgr; 56 57 /// SymMgr - Object that manages the symbol information. 58 SymbolManager& SymMgr; 59 60 /// svalBuilder - SValBuilder object that creates SVals from expressions. 61 SValBuilder &svalBuilder; 62 63 /// EntryNode - The immediate predecessor node. 64 ExplodedNode *EntryNode; 65 66 /// CleanedState - The state for EntryNode "cleaned" of all dead 67 /// variables and symbols (as determined by a liveness analysis). 68 const ProgramState *CleanedState; 69 70 /// currentStmt - The current block-level statement. 71 const Stmt *currentStmt; 72 unsigned int currentStmtIdx; 73 const NodeBuilderContext *currentBuilderContext; 74 75 /// Obj-C Class Identifiers. 76 IdentifierInfo* NSExceptionII; 77 78 /// Obj-C Selectors. 79 Selector* NSExceptionInstanceRaiseSelectors; 80 Selector RaiseSel; 81 82 /// Whether or not GC is enabled in this analysis. 83 bool ObjCGCEnabled; 84 85 /// The BugReporter associated with this engine. It is important that 86 /// this object be placed at the very end of member variables so that its 87 /// destructor is called before the rest of the ExprEngine is destroyed. 88 GRBugReporter BR; 89 90public: 91 ExprEngine(AnalysisManager &mgr, bool gcEnabled); 92 93 ~ExprEngine(); 94 95 void ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) { 96 Engine.ExecuteWorkList(L, Steps, 0); 97 } 98 99 /// Execute the work list with an initial state. Nodes that reaches the exit 100 /// of the function are added into the Dst set, which represent the exit 101 /// state of the function call. 102 void ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps, 103 const ProgramState *InitState, 104 ExplodedNodeSet &Dst) { 105 Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst); 106 } 107 108 /// getContext - Return the ASTContext associated with this analysis. 109 ASTContext &getContext() const { return AMgr.getASTContext(); } 110 111 virtual AnalysisManager &getAnalysisManager() { return AMgr; } 112 113 CheckerManager &getCheckerManager() const { 114 return *AMgr.getCheckerManager(); 115 } 116 117 SValBuilder &getSValBuilder() { return svalBuilder; } 118 119 BugReporter& getBugReporter() { return BR; } 120 121 StmtNodeBuilder &getBuilder() { assert(Builder); return *Builder; } 122 const NodeBuilderContext &getBuilderContext() { 123 assert(currentBuilderContext); 124 return *currentBuilderContext; 125 } 126 127 bool isObjCGCEnabled() { return ObjCGCEnabled; } 128 129 const Stmt *getStmt() const; 130 131 void GenerateAutoTransition(ExplodedNode *N); 132 133 /// ViewGraph - Visualize the ExplodedGraph created by executing the 134 /// simulation. 135 void ViewGraph(bool trim = false); 136 137 void ViewGraph(ExplodedNode** Beg, ExplodedNode** End); 138 139 /// getInitialState - Return the initial state used for the root vertex 140 /// in the ExplodedGraph. 141 const ProgramState *getInitialState(const LocationContext *InitLoc); 142 143 ExplodedGraph& getGraph() { return G; } 144 const ExplodedGraph& getGraph() const { return G; } 145 146 /// processCFGElement - Called by CoreEngine. Used to generate new successor 147 /// nodes by processing the 'effects' of a CFG element. 148 void processCFGElement(const CFGElement E, ExplodedNode *Pred, 149 unsigned StmtIdx, NodeBuilderContext *Ctx); 150 151 void ProcessStmt(const CFGStmt S, ExplodedNode *Pred); 152 153 void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred); 154 155 void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred); 156 157 void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D, 158 StmtNodeBuilder &builder, ExplodedNode *Pred); 159 void ProcessBaseDtor(const CFGBaseDtor D, StmtNodeBuilder &builder); 160 void ProcessMemberDtor(const CFGMemberDtor D, StmtNodeBuilder &builder); 161 void ProcessTemporaryDtor(const CFGTemporaryDtor D, 162 StmtNodeBuilder &builder); 163 164 /// Called by CoreEngine when processing the entrance of a CFGBlock. 165 virtual void processCFGBlockEntrance(ExplodedNodeSet &dstNodes, 166 GenericNodeBuilder<BlockEntrance> &nodeBuilder); 167 168 /// ProcessBranch - Called by CoreEngine. Used to generate successor 169 /// nodes by processing the 'effects' of a branch condition. 170 void processBranch(const Stmt *Condition, const Stmt *Term, 171 NodeBuilderContext& BuilderCtx, 172 ExplodedNode *Pred, 173 ExplodedNodeSet &Dst, 174 const CFGBlock *DstT, 175 const CFGBlock *DstF); 176 177 /// processIndirectGoto - Called by CoreEngine. Used to generate successor 178 /// nodes by processing the 'effects' of a computed goto jump. 179 void processIndirectGoto(IndirectGotoNodeBuilder& builder); 180 181 /// ProcessSwitch - Called by CoreEngine. Used to generate successor 182 /// nodes by processing the 'effects' of a switch statement. 183 void processSwitch(SwitchNodeBuilder& builder); 184 185 /// ProcessEndPath - Called by CoreEngine. Used to generate end-of-path 186 /// nodes when the control reaches the end of a function. 187 void processEndOfFunction(EndOfFunctionNodeBuilder& builder); 188 189 /// Generate the entry node of the callee. 190 void processCallEnter(CallEnterNodeBuilder &builder); 191 192 /// Generate the first post callsite node. 193 void processCallExit(CallExitNodeBuilder &builder); 194 195 /// Called by CoreEngine when the analysis worklist has terminated. 196 void processEndWorklist(bool hasWorkRemaining); 197 198 /// evalAssume - Callback function invoked by the ConstraintManager when 199 /// making assumptions about state values. 200 const ProgramState *processAssume(const ProgramState *state, SVal cond,bool assumption); 201 202 /// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a 203 /// region change should trigger a processRegionChanges update. 204 bool wantsRegionChangeUpdate(const ProgramState *state); 205 206 /// processRegionChanges - Called by ProgramStateManager whenever a change is made 207 /// to the store. Used to update checkers that track region values. 208 const ProgramState * 209 processRegionChanges(const ProgramState *state, 210 const StoreManager::InvalidatedSymbols *invalidated, 211 ArrayRef<const MemRegion *> ExplicitRegions, 212 ArrayRef<const MemRegion *> Regions); 213 214 /// printState - Called by ProgramStateManager to print checker-specific data. 215 void printState(raw_ostream &Out, const ProgramState *State, 216 const char *NL, const char *Sep); 217 218 virtual ProgramStateManager& getStateManager() { return StateMgr; } 219 220 StoreManager& getStoreManager() { return StateMgr.getStoreManager(); } 221 222 ConstraintManager& getConstraintManager() { 223 return StateMgr.getConstraintManager(); 224 } 225 226 // FIXME: Remove when we migrate over to just using SValBuilder. 227 BasicValueFactory& getBasicVals() { 228 return StateMgr.getBasicVals(); 229 } 230 const BasicValueFactory& getBasicVals() const { 231 return StateMgr.getBasicVals(); 232 } 233 234 // FIXME: Remove when we migrate over to just using ValueManager. 235 SymbolManager& getSymbolManager() { return SymMgr; } 236 const SymbolManager& getSymbolManager() const { return SymMgr; } 237 238 // Functions for external checking of whether we have unfinished work 239 bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); } 240 bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); } 241 bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); } 242 243 const CoreEngine &getCoreEngine() const { return Engine; } 244 245public: 246 ExplodedNode *MakeNode(ExplodedNodeSet &Dst, const Stmt *S, 247 ExplodedNode *Pred, const ProgramState *St, 248 ProgramPoint::Kind K = ProgramPoint::PostStmtKind, 249 const ProgramPointTag *tag = 0); 250 251 /// Visit - Transfer function logic for all statements. Dispatches to 252 /// other functions that handle specific kinds of statements. 253 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst); 254 255 /// VisitArraySubscriptExpr - Transfer function for array accesses. 256 void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr *Ex, 257 ExplodedNode *Pred, 258 ExplodedNodeSet &Dst); 259 260 /// VisitAsmStmt - Transfer function logic for inline asm. 261 void VisitAsmStmt(const AsmStmt *A, ExplodedNode *Pred, ExplodedNodeSet &Dst); 262 263 void VisitAsmStmtHelperOutputs(const AsmStmt *A, 264 AsmStmt::const_outputs_iterator I, 265 AsmStmt::const_outputs_iterator E, 266 ExplodedNode *Pred, ExplodedNodeSet &Dst); 267 268 void VisitAsmStmtHelperInputs(const AsmStmt *A, 269 AsmStmt::const_inputs_iterator I, 270 AsmStmt::const_inputs_iterator E, 271 ExplodedNode *Pred, ExplodedNodeSet &Dst); 272 273 /// VisitBlockExpr - Transfer function logic for BlockExprs. 274 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 275 ExplodedNodeSet &Dst); 276 277 /// VisitBinaryOperator - Transfer function logic for binary operators. 278 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred, 279 ExplodedNodeSet &Dst); 280 281 282 /// VisitCall - Transfer function for function calls. 283 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 284 ExplodedNodeSet &Dst); 285 286 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 287 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 288 ExplodedNodeSet &Dst); 289 290 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 291 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 292 ExplodedNode *Pred, ExplodedNodeSet &Dst); 293 294 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 295 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D, 296 ExplodedNode *Pred, ExplodedNodeSet &Dst); 297 298 /// VisitDeclStmt - Transfer function logic for DeclStmts. 299 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 300 ExplodedNodeSet &Dst); 301 302 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 303 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R, 304 ExplodedNode *Pred, ExplodedNodeSet &Dst); 305 306 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred, 307 ExplodedNodeSet &Dst); 308 309 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 310 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 311 ExplodedNodeSet &Dst); 312 313 /// VisitMemberExpr - Transfer function for member expressions. 314 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred, 315 ExplodedNodeSet &Dst); 316 317 /// Transfer function logic for ObjCAtSynchronizedStmts. 318 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 319 ExplodedNode *Pred, ExplodedNodeSet &Dst); 320 321 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 322 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred, 323 ExplodedNodeSet &Dst); 324 325 /// VisitObjCForCollectionStmt - Transfer function logic for 326 /// ObjCForCollectionStmt. 327 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S, 328 ExplodedNode *Pred, ExplodedNodeSet &Dst); 329 330 void VisitObjCMessage(const ObjCMessage &msg, ExplodedNode *Pred, 331 ExplodedNodeSet &Dst); 332 333 /// VisitReturnStmt - Transfer function logic for return statements. 334 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred, 335 ExplodedNodeSet &Dst); 336 337 /// VisitOffsetOfExpr - Transfer function for offsetof. 338 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred, 339 ExplodedNodeSet &Dst); 340 341 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 342 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 343 ExplodedNode *Pred, ExplodedNodeSet &Dst); 344 345 /// VisitUnaryOperator - Transfer function logic for unary operators. 346 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred, 347 ExplodedNodeSet &Dst); 348 349 /// Handle ++ and -- (both pre- and post-increment). 350 void VisitIncrementDecrementOperator(const UnaryOperator* U, 351 ExplodedNode *Pred, 352 ExplodedNodeSet &Dst); 353 354 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 355 ExplodedNodeSet & Dst); 356 357 void VisitCXXTemporaryObjectExpr(const CXXTemporaryObjectExpr *expr, 358 ExplodedNode *Pred, ExplodedNodeSet &Dst) { 359 VisitCXXConstructExpr(expr, 0, Pred, Dst); 360 } 361 362 void VisitCXXConstructExpr(const CXXConstructExpr *E, const MemRegion *Dest, 363 ExplodedNode *Pred, ExplodedNodeSet &Dst); 364 365 void VisitCXXDestructor(const CXXDestructorDecl *DD, 366 const MemRegion *Dest, const Stmt *S, 367 ExplodedNode *Pred, ExplodedNodeSet &Dst); 368 369 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 370 ExplodedNodeSet &Dst); 371 372 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 373 ExplodedNodeSet &Dst); 374 375 void VisitAggExpr(const Expr *E, const MemRegion *Dest, ExplodedNode *Pred, 376 ExplodedNodeSet &Dst); 377 378 /// Create a C++ temporary object for an rvalue. 379 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 380 ExplodedNode *Pred, 381 ExplodedNodeSet &Dst); 382 383 /// Synthesize CXXThisRegion. 384 const CXXThisRegion *getCXXThisRegion(const CXXRecordDecl *RD, 385 const StackFrameContext *SFC); 386 387 const CXXThisRegion *getCXXThisRegion(const CXXMethodDecl *decl, 388 const StackFrameContext *frameCtx); 389 390 /// Evaluate arguments with a work list algorithm. 391 void evalArguments(ConstExprIterator AI, ConstExprIterator AE, 392 const FunctionProtoType *FnType, 393 ExplodedNode *Pred, ExplodedNodeSet &Dst, 394 bool FstArgAsLValue = false); 395 396 /// Evaluate callee expression (for a function call). 397 void evalCallee(const CallExpr *callExpr, const ExplodedNodeSet &src, 398 ExplodedNodeSet &dest); 399 400 /// evalEagerlyAssume - Given the nodes in 'Src', eagerly assume symbolic 401 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 402 /// with those assumptions. 403 void evalEagerlyAssume(ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 404 const Expr *Ex); 405 406 std::pair<const ProgramPointTag *, const ProgramPointTag*> 407 getEagerlyAssumeTags(); 408 409 SVal evalMinus(SVal X) { 410 return X.isValid() ? svalBuilder.evalMinus(cast<NonLoc>(X)) : X; 411 } 412 413 SVal evalComplement(SVal X) { 414 return X.isValid() ? svalBuilder.evalComplement(cast<NonLoc>(X)) : X; 415 } 416 417public: 418 419 SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op, 420 NonLoc L, NonLoc R, QualType T) { 421 return svalBuilder.evalBinOpNN(state, op, L, R, T); 422 } 423 424 SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op, 425 NonLoc L, SVal R, QualType T) { 426 return R.isValid() ? svalBuilder.evalBinOpNN(state,op,L, cast<NonLoc>(R), T) : R; 427 } 428 429 SVal evalBinOp(const ProgramState *ST, BinaryOperator::Opcode Op, 430 SVal LHS, SVal RHS, QualType T) { 431 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 432 } 433 434protected: 435 void evalObjCMessage(PureStmtNodeBuilder &Bldr, const ObjCMessage &msg, 436 ExplodedNode *Pred, const ProgramState *state, 437 bool GenSink); 438 439 const ProgramState *invalidateArguments(const ProgramState *State, 440 const CallOrObjCMessage &Call, 441 const LocationContext *LC); 442 443 const ProgramState *MarkBranch(const ProgramState *St, const Stmt *Terminator, 444 bool branchTaken); 445 446 /// evalBind - Handle the semantics of binding a value to a specific location. 447 /// This method is used by evalStore, VisitDeclStmt, and others. 448 void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred, 449 SVal location, SVal Val, bool atDeclInit = false, 450 ProgramPoint::Kind PP = ProgramPoint::PostStmtKind); 451 452public: 453 // FIXME: 'tag' should be removed, and a LocationContext should be used 454 // instead. 455 // FIXME: Comment on the meaning of the arguments, when 'St' may not 456 // be the same as Pred->state, and when 'location' may not be the 457 // same as state->getLValue(Ex). 458 /// Simulate a read of the result of Ex. 459 void evalLoad(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred, 460 const ProgramState *St, SVal location, const ProgramPointTag *tag = 0, 461 QualType LoadTy = QualType()); 462 463 // FIXME: 'tag' should be removed, and a LocationContext should be used 464 // instead. 465 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE, 466 ExplodedNode *Pred, const ProgramState *St, SVal TargetLV, SVal Val, 467 const ProgramPointTag *tag = 0); 468private: 469 void evalLoadCommon(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred, 470 const ProgramState *St, SVal location, const ProgramPointTag *tag, 471 QualType LoadTy); 472 473 // FIXME: 'tag' should be removed, and a LocationContext should be used 474 // instead. 475 void evalLocation(ExplodedNodeSet &Dst, const Stmt *S, ExplodedNode *Pred, 476 const ProgramState *St, SVal location, 477 const ProgramPointTag *tag, bool isLoad); 478 479 bool InlineCall(ExplodedNodeSet &Dst, const CallExpr *CE, ExplodedNode *Pred); 480 481 482public: 483 /// Returns true if calling the specific function or method would possibly 484 /// cause global variables to be invalidated. 485 bool doesInvalidateGlobals(const CallOrObjCMessage &callOrMessage) const; 486 487}; 488 489} // end ento namespace 490 491} // end clang namespace 492 493#endif 494