ExprEngine.h revision e38dd95dddb8f1b38469c8d0e28aa1c660489324
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/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 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 /// 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 ProgramState *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 ProgramState *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 ProgramState *processAssume(const ProgramState *state, SVal cond,bool assumption); 185 186 /// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a 187 /// region change should trigger a processRegionChanges update. 188 bool wantsRegionChangeUpdate(const ProgramState *state); 189 190 /// processRegionChanges - Called by ProgramStateManager whenever a change is made 191 /// to the store. Used to update checkers that track region values. 192 const ProgramState * 193 processRegionChanges(const ProgramState *state, 194 const StoreManager::InvalidatedSymbols *invalidated, 195 ArrayRef<const MemRegion *> ExplicitRegions, 196 ArrayRef<const MemRegion *> Regions); 197 198 virtual ProgramStateManager& 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 225public: 226 ExplodedNode *MakeNode(ExplodedNodeSet &Dst, const Stmt *S, 227 ExplodedNode *Pred, const ProgramState *St, 228 ProgramPoint::Kind K = ProgramPoint::PostStmtKind, 229 const ProgramPointTag *tag = 0); 230 231 /// Visit - Transfer function logic for all statements. Dispatches to 232 /// other functions that handle specific kinds of statements. 233 void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst); 234 235 /// VisitArraySubscriptExpr - Transfer function for array accesses. 236 void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr *Ex, 237 ExplodedNode *Pred, 238 ExplodedNodeSet &Dst); 239 240 /// VisitAsmStmt - Transfer function logic for inline asm. 241 void VisitAsmStmt(const AsmStmt *A, ExplodedNode *Pred, ExplodedNodeSet &Dst); 242 243 void VisitAsmStmtHelperOutputs(const AsmStmt *A, 244 AsmStmt::const_outputs_iterator I, 245 AsmStmt::const_outputs_iterator E, 246 ExplodedNode *Pred, ExplodedNodeSet &Dst); 247 248 void VisitAsmStmtHelperInputs(const AsmStmt *A, 249 AsmStmt::const_inputs_iterator I, 250 AsmStmt::const_inputs_iterator E, 251 ExplodedNode *Pred, ExplodedNodeSet &Dst); 252 253 /// VisitBlockExpr - Transfer function logic for BlockExprs. 254 void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred, 255 ExplodedNodeSet &Dst); 256 257 /// VisitBinaryOperator - Transfer function logic for binary operators. 258 void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred, 259 ExplodedNodeSet &Dst); 260 261 262 /// VisitCall - Transfer function for function calls. 263 void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred, 264 ExplodedNodeSet &Dst); 265 266 /// VisitCast - Transfer function logic for all casts (implicit and explicit). 267 void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred, 268 ExplodedNodeSet &Dst); 269 270 /// VisitCompoundLiteralExpr - Transfer function logic for compound literals. 271 void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL, 272 ExplodedNode *Pred, ExplodedNodeSet &Dst); 273 274 /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs. 275 void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D, 276 ExplodedNode *Pred, ExplodedNodeSet &Dst); 277 278 /// VisitDeclStmt - Transfer function logic for DeclStmts. 279 void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred, 280 ExplodedNodeSet &Dst); 281 282 /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose 283 void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R, 284 ExplodedNode *Pred, ExplodedNodeSet &Dst); 285 286 void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred, 287 ExplodedNodeSet &Dst); 288 289 /// VisitLogicalExpr - Transfer function logic for '&&', '||' 290 void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred, 291 ExplodedNodeSet &Dst); 292 293 /// VisitMemberExpr - Transfer function for member expressions. 294 void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred, 295 ExplodedNodeSet &Dst); 296 297 /// Transfer function logic for ObjCAtSynchronizedStmts. 298 void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S, 299 ExplodedNode *Pred, ExplodedNodeSet &Dst); 300 301 /// Transfer function logic for computing the lvalue of an Objective-C ivar. 302 void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred, 303 ExplodedNodeSet &Dst); 304 305 /// VisitObjCForCollectionStmt - Transfer function logic for 306 /// ObjCForCollectionStmt. 307 void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S, 308 ExplodedNode *Pred, ExplodedNodeSet &Dst); 309 310 void VisitObjCMessage(const ObjCMessage &msg, ExplodedNode *Pred, 311 ExplodedNodeSet &Dst); 312 313 /// VisitReturnStmt - Transfer function logic for return statements. 314 void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred, 315 ExplodedNodeSet &Dst); 316 317 /// VisitOffsetOfExpr - Transfer function for offsetof. 318 void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred, 319 ExplodedNodeSet &Dst); 320 321 /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof. 322 void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex, 323 ExplodedNode *Pred, ExplodedNodeSet &Dst); 324 325 /// VisitUnaryOperator - Transfer function logic for unary operators. 326 void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred, 327 ExplodedNodeSet &Dst); 328 329 void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred, 330 ExplodedNodeSet & Dst); 331 332 void VisitCXXTemporaryObjectExpr(const CXXTemporaryObjectExpr *expr, 333 ExplodedNode *Pred, ExplodedNodeSet &Dst) { 334 VisitCXXConstructExpr(expr, 0, Pred, Dst); 335 } 336 337 void VisitCXXConstructExpr(const CXXConstructExpr *E, const MemRegion *Dest, 338 ExplodedNode *Pred, ExplodedNodeSet &Dst); 339 340 void VisitCXXDestructor(const CXXDestructorDecl *DD, 341 const MemRegion *Dest, const Stmt *S, 342 ExplodedNode *Pred, ExplodedNodeSet &Dst); 343 344 void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred, 345 ExplodedNodeSet &Dst); 346 347 void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred, 348 ExplodedNodeSet &Dst); 349 350 void VisitAggExpr(const Expr *E, const MemRegion *Dest, ExplodedNode *Pred, 351 ExplodedNodeSet &Dst); 352 353 /// Create a C++ temporary object for an rvalue. 354 void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME, 355 ExplodedNode *Pred, 356 ExplodedNodeSet &Dst); 357 358 /// Synthesize CXXThisRegion. 359 const CXXThisRegion *getCXXThisRegion(const CXXRecordDecl *RD, 360 const StackFrameContext *SFC); 361 362 const CXXThisRegion *getCXXThisRegion(const CXXMethodDecl *decl, 363 const StackFrameContext *frameCtx); 364 365 /// Evaluate arguments with a work list algorithm. 366 void evalArguments(ConstExprIterator AI, ConstExprIterator AE, 367 const FunctionProtoType *FnType, 368 ExplodedNode *Pred, ExplodedNodeSet &Dst, 369 bool FstArgAsLValue = false); 370 371 /// Evaluate callee expression (for a function call). 372 void evalCallee(const CallExpr *callExpr, const ExplodedNodeSet &src, 373 ExplodedNodeSet &dest); 374 375 /// evalEagerlyAssume - Given the nodes in 'Src', eagerly assume symbolic 376 /// expressions of the form 'x != 0' and generate new nodes (stored in Dst) 377 /// with those assumptions. 378 void evalEagerlyAssume(ExplodedNodeSet &Dst, ExplodedNodeSet &Src, 379 const Expr *Ex); 380 381 std::pair<const ProgramPointTag *, const ProgramPointTag*> 382 getEagerlyAssumeTags(); 383 384 SVal evalMinus(SVal X) { 385 return X.isValid() ? svalBuilder.evalMinus(cast<NonLoc>(X)) : X; 386 } 387 388 SVal evalComplement(SVal X) { 389 return X.isValid() ? svalBuilder.evalComplement(cast<NonLoc>(X)) : X; 390 } 391 392public: 393 394 SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op, 395 NonLoc L, NonLoc R, QualType T) { 396 return svalBuilder.evalBinOpNN(state, op, L, R, T); 397 } 398 399 SVal evalBinOp(const ProgramState *state, BinaryOperator::Opcode op, 400 NonLoc L, SVal R, QualType T) { 401 return R.isValid() ? svalBuilder.evalBinOpNN(state,op,L, cast<NonLoc>(R), T) : R; 402 } 403 404 SVal evalBinOp(const ProgramState *ST, BinaryOperator::Opcode Op, 405 SVal LHS, SVal RHS, QualType T) { 406 return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T); 407 } 408 409protected: 410 void evalObjCMessage(ExplodedNodeSet &Dst, const ObjCMessage &msg, 411 ExplodedNode *Pred, const ProgramState *state); 412 413 const ProgramState *invalidateArguments(const ProgramState *State, 414 const CallOrObjCMessage &Call, 415 const LocationContext *LC); 416 417 const ProgramState *MarkBranch(const ProgramState *St, const Stmt *Terminator, 418 bool branchTaken); 419 420 /// evalBind - Handle the semantics of binding a value to a specific location. 421 /// This method is used by evalStore, VisitDeclStmt, and others. 422 void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred, 423 const ProgramState *St, SVal location, SVal Val, 424 bool atDeclInit = false); 425 426public: 427 // FIXME: 'tag' should be removed, and a LocationContext should be used 428 // instead. 429 // FIXME: Comment on the meaning of the arguments, when 'St' may not 430 // be the same as Pred->state, and when 'location' may not be the 431 // same as state->getLValue(Ex). 432 /// Simulate a read of the result of Ex. 433 void evalLoad(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred, 434 const ProgramState *St, SVal location, const ProgramPointTag *tag = 0, 435 QualType LoadTy = QualType()); 436 437 // FIXME: 'tag' should be removed, and a LocationContext should be used 438 // instead. 439 void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE, 440 ExplodedNode *Pred, const ProgramState *St, SVal TargetLV, SVal Val, 441 const ProgramPointTag *tag = 0); 442private: 443 void evalLoadCommon(ExplodedNodeSet &Dst, const Expr *Ex, ExplodedNode *Pred, 444 const ProgramState *St, SVal location, const ProgramPointTag *tag, 445 QualType LoadTy); 446 447 // FIXME: 'tag' should be removed, and a LocationContext should be used 448 // instead. 449 void evalLocation(ExplodedNodeSet &Dst, const Stmt *S, ExplodedNode *Pred, 450 const ProgramState *St, SVal location, 451 const ProgramPointTag *tag, bool isLoad); 452 453 bool InlineCall(ExplodedNodeSet &Dst, const CallExpr *CE, ExplodedNode *Pred); 454 455 456public: 457 /// Returns true if calling the specific function or method would possibly 458 /// cause global variables to be invalidated. 459 bool doesInvalidateGlobals(const CallOrObjCMessage &callOrMessage) const; 460 461}; 462 463} // end ento namespace 464 465} // end clang namespace 466 467#endif 468