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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_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
17 #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
18 
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/Type.h"
21 #include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
22 #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
23 #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
24 #include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
25 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
26 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
27 #include "clang/StaticAnalyzer/Core/PathSensitive/SubEngine.h"
28 
29 namespace clang {
30 
31 class AnalysisDeclContextManager;
32 class CXXCatchStmt;
33 class CXXConstructExpr;
34 class CXXDeleteExpr;
35 class CXXNewExpr;
36 class CXXTemporaryObjectExpr;
37 class CXXThisExpr;
38 class MaterializeTemporaryExpr;
39 class ObjCAtSynchronizedStmt;
40 class ObjCForCollectionStmt;
41 
42 namespace ento {
43 
44 class AnalysisManager;
45 class CallEvent;
46 class CXXConstructorCall;
47 
48 class ExprEngine : public SubEngine {
49 public:
50   /// The modes of inlining, which override the default analysis-wide settings.
51   enum InliningModes {
52     /// Follow the default settings for inlining callees.
53     Inline_Regular = 0,
54     /// Do minimal inlining of callees.
55     Inline_Minimal = 0x1
56   };
57 
58 private:
59   AnalysisManager &AMgr;
60 
61   AnalysisDeclContextManager &AnalysisDeclContexts;
62 
63   CoreEngine Engine;
64 
65   /// G - the simulation graph.
66   ExplodedGraph& G;
67 
68   /// StateMgr - Object that manages the data for all created states.
69   ProgramStateManager StateMgr;
70 
71   /// SymMgr - Object that manages the symbol information.
72   SymbolManager& SymMgr;
73 
74   /// svalBuilder - SValBuilder object that creates SVals from expressions.
75   SValBuilder &svalBuilder;
76 
77   unsigned int currStmtIdx;
78   const NodeBuilderContext *currBldrCtx;
79 
80   /// Helper object to determine if an Objective-C message expression
81   /// implicitly never returns.
82   ObjCNoReturn ObjCNoRet;
83 
84   /// Whether or not GC is enabled in this analysis.
85   bool ObjCGCEnabled;
86 
87   /// The BugReporter associated with this engine.  It is important that
88   ///  this object be placed at the very end of member variables so that its
89   ///  destructor is called before the rest of the ExprEngine is destroyed.
90   GRBugReporter BR;
91 
92   /// The functions which have been analyzed through inlining. This is owned by
93   /// AnalysisConsumer. It can be null.
94   SetOfConstDecls *VisitedCallees;
95 
96   /// The flag, which specifies the mode of inlining for the engine.
97   InliningModes HowToInline;
98 
99 public:
100   ExprEngine(AnalysisManager &mgr, bool gcEnabled,
101              SetOfConstDecls *VisitedCalleesIn,
102              FunctionSummariesTy *FS,
103              InliningModes HowToInlineIn);
104 
105   ~ExprEngine() override;
106 
107   /// Returns true if there is still simulation state on the worklist.
108   bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) {
109     return Engine.ExecuteWorkList(L, Steps, nullptr);
110   }
111 
112   /// Execute the work list with an initial state. Nodes that reaches the exit
113   /// of the function are added into the Dst set, which represent the exit
114   /// state of the function call. Returns true if there is still simulation
115   /// state on the worklist.
ExecuteWorkListWithInitialState(const LocationContext * L,unsigned Steps,ProgramStateRef InitState,ExplodedNodeSet & Dst)116   bool ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps,
117                                        ProgramStateRef InitState,
118                                        ExplodedNodeSet &Dst) {
119     return Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst);
120   }
121 
122   /// getContext - Return the ASTContext associated with this analysis.
getContext()123   ASTContext &getContext() const { return AMgr.getASTContext(); }
124 
getAnalysisManager()125   AnalysisManager &getAnalysisManager() override { return AMgr; }
126 
getCheckerManager()127   CheckerManager &getCheckerManager() const {
128     return *AMgr.getCheckerManager();
129   }
130 
getSValBuilder()131   SValBuilder &getSValBuilder() { return svalBuilder; }
132 
getBugReporter()133   BugReporter& getBugReporter() { return BR; }
134 
getBuilderContext()135   const NodeBuilderContext &getBuilderContext() {
136     assert(currBldrCtx);
137     return *currBldrCtx;
138   }
139 
isObjCGCEnabled()140   bool isObjCGCEnabled() { return ObjCGCEnabled; }
141 
142   const Stmt *getStmt() const;
143 
144   void GenerateAutoTransition(ExplodedNode *N);
145   void enqueueEndOfPath(ExplodedNodeSet &S);
146   void GenerateCallExitNode(ExplodedNode *N);
147 
148   /// Visualize the ExplodedGraph created by executing the simulation.
149   void ViewGraph(bool trim = false);
150 
151   /// Visualize a trimmed ExplodedGraph that only contains paths to the given
152   /// nodes.
153   void ViewGraph(ArrayRef<const ExplodedNode*> Nodes);
154 
155   /// getInitialState - Return the initial state used for the root vertex
156   ///  in the ExplodedGraph.
157   ProgramStateRef getInitialState(const LocationContext *InitLoc) override;
158 
getGraph()159   ExplodedGraph& getGraph() { return G; }
getGraph()160   const ExplodedGraph& getGraph() const { return G; }
161 
162   /// \brief Run the analyzer's garbage collection - remove dead symbols and
163   /// bindings from the state.
164   ///
165   /// Checkers can participate in this process with two callbacks:
166   /// \c checkLiveSymbols and \c checkDeadSymbols. See the CheckerDocumentation
167   /// class for more information.
168   ///
169   /// \param Node The predecessor node, from which the processing should start.
170   /// \param Out The returned set of output nodes.
171   /// \param ReferenceStmt The statement which is about to be processed.
172   ///        Everything needed for this statement should be considered live.
173   ///        A null statement means that everything in child LocationContexts
174   ///        is dead.
175   /// \param LC The location context of the \p ReferenceStmt. A null location
176   ///        context means that we have reached the end of analysis and that
177   ///        all statements and local variables should be considered dead.
178   /// \param DiagnosticStmt Used as a location for any warnings that should
179   ///        occur while removing the dead (e.g. leaks). By default, the
180   ///        \p ReferenceStmt is used.
181   /// \param K Denotes whether this is a pre- or post-statement purge. This
182   ///        must only be ProgramPoint::PostStmtPurgeDeadSymbolsKind if an
183   ///        entire location context is being cleared, in which case the
184   ///        \p ReferenceStmt must either be a ReturnStmt or \c NULL. Otherwise,
185   ///        it must be ProgramPoint::PreStmtPurgeDeadSymbolsKind (the default)
186   ///        and \p ReferenceStmt must be valid (non-null).
187   void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out,
188             const Stmt *ReferenceStmt, const LocationContext *LC,
189             const Stmt *DiagnosticStmt = nullptr,
190             ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind);
191 
192   /// processCFGElement - Called by CoreEngine. Used to generate new successor
193   ///  nodes by processing the 'effects' of a CFG element.
194   void processCFGElement(const CFGElement E, ExplodedNode *Pred,
195                          unsigned StmtIdx, NodeBuilderContext *Ctx) override;
196 
197   void ProcessStmt(const CFGStmt S, ExplodedNode *Pred);
198 
199   void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred);
200 
201   void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred);
202 
203   void ProcessNewAllocator(const CXXNewExpr *NE, ExplodedNode *Pred);
204 
205   void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D,
206                                ExplodedNode *Pred, ExplodedNodeSet &Dst);
207   void ProcessDeleteDtor(const CFGDeleteDtor D,
208                          ExplodedNode *Pred, ExplodedNodeSet &Dst);
209   void ProcessBaseDtor(const CFGBaseDtor D,
210                        ExplodedNode *Pred, ExplodedNodeSet &Dst);
211   void ProcessMemberDtor(const CFGMemberDtor D,
212                          ExplodedNode *Pred, ExplodedNodeSet &Dst);
213   void ProcessTemporaryDtor(const CFGTemporaryDtor D,
214                             ExplodedNode *Pred, ExplodedNodeSet &Dst);
215 
216   /// Called by CoreEngine when processing the entrance of a CFGBlock.
217   void processCFGBlockEntrance(const BlockEdge &L,
218                                NodeBuilderWithSinks &nodeBuilder,
219                                ExplodedNode *Pred) override;
220 
221   /// ProcessBranch - Called by CoreEngine.  Used to generate successor
222   ///  nodes by processing the 'effects' of a branch condition.
223   void processBranch(const Stmt *Condition, const Stmt *Term,
224                      NodeBuilderContext& BuilderCtx,
225                      ExplodedNode *Pred,
226                      ExplodedNodeSet &Dst,
227                      const CFGBlock *DstT,
228                      const CFGBlock *DstF) override;
229 
230   /// Called by CoreEngine.
231   /// Used to generate successor nodes for temporary destructors depending
232   /// on whether the corresponding constructor was visited.
233   void processCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE,
234                                      NodeBuilderContext &BldCtx,
235                                      ExplodedNode *Pred, ExplodedNodeSet &Dst,
236                                      const CFGBlock *DstT,
237                                      const CFGBlock *DstF) override;
238 
239   /// Called by CoreEngine.  Used to processing branching behavior
240   /// at static initalizers.
241   void processStaticInitializer(const DeclStmt *DS,
242                                 NodeBuilderContext& BuilderCtx,
243                                 ExplodedNode *Pred,
244                                 ExplodedNodeSet &Dst,
245                                 const CFGBlock *DstT,
246                                 const CFGBlock *DstF) override;
247 
248   /// processIndirectGoto - Called by CoreEngine.  Used to generate successor
249   ///  nodes by processing the 'effects' of a computed goto jump.
250   void processIndirectGoto(IndirectGotoNodeBuilder& builder) override;
251 
252   /// ProcessSwitch - Called by CoreEngine.  Used to generate successor
253   ///  nodes by processing the 'effects' of a switch statement.
254   void processSwitch(SwitchNodeBuilder& builder) override;
255 
256   /// Called by CoreEngine.  Used to notify checkers that processing a
257   /// function has begun. Called for both inlined and and top-level functions.
258   void processBeginOfFunction(NodeBuilderContext &BC,
259                               ExplodedNode *Pred, ExplodedNodeSet &Dst,
260                               const BlockEdge &L) override;
261 
262   /// Called by CoreEngine.  Used to notify checkers that processing a
263   /// function has ended. Called for both inlined and and top-level functions.
264   void processEndOfFunction(NodeBuilderContext& BC,
265                             ExplodedNode *Pred) override;
266 
267   /// Remove dead bindings/symbols before exiting a function.
268   void removeDeadOnEndOfFunction(NodeBuilderContext& BC,
269                                  ExplodedNode *Pred,
270                                  ExplodedNodeSet &Dst);
271 
272   /// Generate the entry node of the callee.
273   void processCallEnter(NodeBuilderContext& BC, CallEnter CE,
274                         ExplodedNode *Pred) override;
275 
276   /// Generate the sequence of nodes that simulate the call exit and the post
277   /// visit for CallExpr.
278   void processCallExit(ExplodedNode *Pred) override;
279 
280   /// Called by CoreEngine when the analysis worklist has terminated.
281   void processEndWorklist(bool hasWorkRemaining) override;
282 
283   /// evalAssume - Callback function invoked by the ConstraintManager when
284   ///  making assumptions about state values.
285   ProgramStateRef processAssume(ProgramStateRef state, SVal cond,
286                                 bool assumption) override;
287 
288   /// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a
289   ///  region change should trigger a processRegionChanges update.
290   bool wantsRegionChangeUpdate(ProgramStateRef state) override;
291 
292   /// processRegionChanges - Called by ProgramStateManager whenever a change is made
293   ///  to the store. Used to update checkers that track region values.
294   ProgramStateRef
295   processRegionChanges(ProgramStateRef state,
296                        const InvalidatedSymbols *invalidated,
297                        ArrayRef<const MemRegion *> ExplicitRegions,
298                        ArrayRef<const MemRegion *> Regions,
299                        const CallEvent *Call) override;
300 
301   /// printState - Called by ProgramStateManager to print checker-specific data.
302   void printState(raw_ostream &Out, ProgramStateRef State,
303                   const char *NL, const char *Sep) override;
304 
getStateManager()305   ProgramStateManager& getStateManager() override { return StateMgr; }
306 
getStoreManager()307   StoreManager& getStoreManager() { return StateMgr.getStoreManager(); }
308 
getConstraintManager()309   ConstraintManager& getConstraintManager() {
310     return StateMgr.getConstraintManager();
311   }
312 
313   // FIXME: Remove when we migrate over to just using SValBuilder.
getBasicVals()314   BasicValueFactory& getBasicVals() {
315     return StateMgr.getBasicVals();
316   }
317 
318   // FIXME: Remove when we migrate over to just using ValueManager.
getSymbolManager()319   SymbolManager& getSymbolManager() { return SymMgr; }
getSymbolManager()320   const SymbolManager& getSymbolManager() const { return SymMgr; }
321 
322   // Functions for external checking of whether we have unfinished work
wasBlocksExhausted()323   bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); }
hasEmptyWorkList()324   bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); }
hasWorkRemaining()325   bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); }
326 
getCoreEngine()327   const CoreEngine &getCoreEngine() const { return Engine; }
328 
329 public:
330   /// Visit - Transfer function logic for all statements.  Dispatches to
331   ///  other functions that handle specific kinds of statements.
332   void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst);
333 
334   /// VisitArraySubscriptExpr - Transfer function for array accesses.
335   void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr *Ex,
336                                    ExplodedNode *Pred,
337                                    ExplodedNodeSet &Dst);
338 
339   /// VisitGCCAsmStmt - Transfer function logic for inline asm.
340   void VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred,
341                        ExplodedNodeSet &Dst);
342 
343   /// VisitMSAsmStmt - Transfer function logic for MS inline asm.
344   void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred,
345                       ExplodedNodeSet &Dst);
346 
347   /// VisitBlockExpr - Transfer function logic for BlockExprs.
348   void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred,
349                       ExplodedNodeSet &Dst);
350 
351   /// VisitLambdaExpr - Transfer function logic for LambdaExprs.
352   void VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred,
353                        ExplodedNodeSet &Dst);
354 
355   /// VisitBinaryOperator - Transfer function logic for binary operators.
356   void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred,
357                            ExplodedNodeSet &Dst);
358 
359 
360   /// VisitCall - Transfer function for function calls.
361   void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred,
362                      ExplodedNodeSet &Dst);
363 
364   /// VisitCast - Transfer function logic for all casts (implicit and explicit).
365   void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred,
366                 ExplodedNodeSet &Dst);
367 
368   /// VisitCompoundLiteralExpr - Transfer function logic for compound literals.
369   void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
370                                 ExplodedNode *Pred, ExplodedNodeSet &Dst);
371 
372   /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs.
373   void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D,
374                               ExplodedNode *Pred, ExplodedNodeSet &Dst);
375 
376   /// VisitDeclStmt - Transfer function logic for DeclStmts.
377   void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred,
378                      ExplodedNodeSet &Dst);
379 
380   /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose
381   void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R,
382                         ExplodedNode *Pred, ExplodedNodeSet &Dst);
383 
384   void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred,
385                          ExplodedNodeSet &Dst);
386 
387   /// VisitLogicalExpr - Transfer function logic for '&&', '||'
388   void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred,
389                         ExplodedNodeSet &Dst);
390 
391   /// VisitMemberExpr - Transfer function for member expressions.
392   void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred,
393                            ExplodedNodeSet &Dst);
394 
395   /// VisitMemberExpr - Transfer function for builtin atomic expressions
396   void VisitAtomicExpr(const AtomicExpr *E, ExplodedNode *Pred,
397                        ExplodedNodeSet &Dst);
398 
399   /// Transfer function logic for ObjCAtSynchronizedStmts.
400   void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S,
401                                    ExplodedNode *Pred, ExplodedNodeSet &Dst);
402 
403   /// Transfer function logic for computing the lvalue of an Objective-C ivar.
404   void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred,
405                                 ExplodedNodeSet &Dst);
406 
407   /// VisitObjCForCollectionStmt - Transfer function logic for
408   ///  ObjCForCollectionStmt.
409   void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S,
410                                   ExplodedNode *Pred, ExplodedNodeSet &Dst);
411 
412   void VisitObjCMessage(const ObjCMessageExpr *ME, ExplodedNode *Pred,
413                         ExplodedNodeSet &Dst);
414 
415   /// VisitReturnStmt - Transfer function logic for return statements.
416   void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred,
417                        ExplodedNodeSet &Dst);
418 
419   /// VisitOffsetOfExpr - Transfer function for offsetof.
420   void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred,
421                          ExplodedNodeSet &Dst);
422 
423   /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
424   void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex,
425                               ExplodedNode *Pred, ExplodedNodeSet &Dst);
426 
427   /// VisitUnaryOperator - Transfer function logic for unary operators.
428   void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred,
429                           ExplodedNodeSet &Dst);
430 
431   /// Handle ++ and -- (both pre- and post-increment).
432   void VisitIncrementDecrementOperator(const UnaryOperator* U,
433                                        ExplodedNode *Pred,
434                                        ExplodedNodeSet &Dst);
435 
436   void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE,
437                                  ExplodedNodeSet &PreVisit,
438                                  ExplodedNodeSet &Dst);
439 
440   void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred,
441                          ExplodedNodeSet &Dst);
442 
443   void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
444                         ExplodedNodeSet & Dst);
445 
446   void VisitCXXConstructExpr(const CXXConstructExpr *E, ExplodedNode *Pred,
447                              ExplodedNodeSet &Dst);
448 
449   void VisitCXXDestructor(QualType ObjectType, const MemRegion *Dest,
450                           const Stmt *S, bool IsBaseDtor,
451                           ExplodedNode *Pred, ExplodedNodeSet &Dst);
452 
453   void VisitCXXNewAllocatorCall(const CXXNewExpr *CNE,
454                                 ExplodedNode *Pred,
455                                 ExplodedNodeSet &Dst);
456 
457   void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
458                        ExplodedNodeSet &Dst);
459 
460   void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred,
461                           ExplodedNodeSet &Dst);
462 
463   /// Create a C++ temporary object for an rvalue.
464   void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME,
465                                 ExplodedNode *Pred,
466                                 ExplodedNodeSet &Dst);
467 
468   /// evalEagerlyAssumeBinOpBifurcation - Given the nodes in 'Src', eagerly assume symbolic
469   ///  expressions of the form 'x != 0' and generate new nodes (stored in Dst)
470   ///  with those assumptions.
471   void evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst, ExplodedNodeSet &Src,
472                          const Expr *Ex);
473 
474   std::pair<const ProgramPointTag *, const ProgramPointTag*>
475     geteagerlyAssumeBinOpBifurcationTags();
476 
evalMinus(SVal X)477   SVal evalMinus(SVal X) {
478     return X.isValid() ? svalBuilder.evalMinus(X.castAs<NonLoc>()) : X;
479   }
480 
evalComplement(SVal X)481   SVal evalComplement(SVal X) {
482     return X.isValid() ? svalBuilder.evalComplement(X.castAs<NonLoc>()) : X;
483   }
484 
485 public:
486 
evalBinOp(ProgramStateRef state,BinaryOperator::Opcode op,NonLoc L,NonLoc R,QualType T)487   SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
488                  NonLoc L, NonLoc R, QualType T) {
489     return svalBuilder.evalBinOpNN(state, op, L, R, T);
490   }
491 
evalBinOp(ProgramStateRef state,BinaryOperator::Opcode op,NonLoc L,SVal R,QualType T)492   SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
493                  NonLoc L, SVal R, QualType T) {
494     return R.isValid() ? svalBuilder.evalBinOpNN(state, op, L,
495                                                  R.castAs<NonLoc>(), T) : R;
496   }
497 
evalBinOp(ProgramStateRef ST,BinaryOperator::Opcode Op,SVal LHS,SVal RHS,QualType T)498   SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op,
499                  SVal LHS, SVal RHS, QualType T) {
500     return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T);
501   }
502 
503 protected:
504   /// evalBind - Handle the semantics of binding a value to a specific location.
505   ///  This method is used by evalStore, VisitDeclStmt, and others.
506   void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred,
507                 SVal location, SVal Val, bool atDeclInit = false,
508                 const ProgramPoint *PP = nullptr);
509 
510   /// Call PointerEscape callback when a value escapes as a result of bind.
511   ProgramStateRef processPointerEscapedOnBind(ProgramStateRef State,
512                                               SVal Loc, SVal Val) override;
513   /// Call PointerEscape callback when a value escapes as a result of
514   /// region invalidation.
515   /// \param[in] ITraits Specifies invalidation traits for regions/symbols.
516   ProgramStateRef notifyCheckersOfPointerEscape(
517                            ProgramStateRef State,
518                            const InvalidatedSymbols *Invalidated,
519                            ArrayRef<const MemRegion *> ExplicitRegions,
520                            ArrayRef<const MemRegion *> Regions,
521                            const CallEvent *Call,
522                            RegionAndSymbolInvalidationTraits &ITraits) override;
523 
524 public:
525   // FIXME: 'tag' should be removed, and a LocationContext should be used
526   // instead.
527   // FIXME: Comment on the meaning of the arguments, when 'St' may not
528   // be the same as Pred->state, and when 'location' may not be the
529   // same as state->getLValue(Ex).
530   /// Simulate a read of the result of Ex.
531   void evalLoad(ExplodedNodeSet &Dst,
532                 const Expr *NodeEx,  /* Eventually will be a CFGStmt */
533                 const Expr *BoundExpr,
534                 ExplodedNode *Pred,
535                 ProgramStateRef St,
536                 SVal location,
537                 const ProgramPointTag *tag = nullptr,
538                 QualType LoadTy = QualType());
539 
540   // FIXME: 'tag' should be removed, and a LocationContext should be used
541   // instead.
542   void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE,
543                  ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val,
544                  const ProgramPointTag *tag = nullptr);
545 
546   /// \brief Create a new state in which the call return value is binded to the
547   /// call origin expression.
548   ProgramStateRef bindReturnValue(const CallEvent &Call,
549                                   const LocationContext *LCtx,
550                                   ProgramStateRef State);
551 
552   /// Evaluate a call, running pre- and post-call checks and allowing checkers
553   /// to be responsible for handling the evaluation of the call itself.
554   void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred,
555                 const CallEvent &Call);
556 
557   /// \brief Default implementation of call evaluation.
558   void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred,
559                        const CallEvent &Call);
560 private:
561   void evalLoadCommon(ExplodedNodeSet &Dst,
562                       const Expr *NodeEx,  /* Eventually will be a CFGStmt */
563                       const Expr *BoundEx,
564                       ExplodedNode *Pred,
565                       ProgramStateRef St,
566                       SVal location,
567                       const ProgramPointTag *tag,
568                       QualType LoadTy);
569 
570   // FIXME: 'tag' should be removed, and a LocationContext should be used
571   // instead.
572   void evalLocation(ExplodedNodeSet &Dst,
573                     const Stmt *NodeEx, /* This will eventually be a CFGStmt */
574                     const Stmt *BoundEx,
575                     ExplodedNode *Pred,
576                     ProgramStateRef St, SVal location,
577                     const ProgramPointTag *tag, bool isLoad);
578 
579   /// Count the stack depth and determine if the call is recursive.
580   void examineStackFrames(const Decl *D, const LocationContext *LCtx,
581                           bool &IsRecursive, unsigned &StackDepth);
582 
583   /// Checks our policies and decides weither the given call should be inlined.
584   bool shouldInlineCall(const CallEvent &Call, const Decl *D,
585                         const ExplodedNode *Pred);
586 
587   bool inlineCall(const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
588                   ExplodedNode *Pred, ProgramStateRef State);
589 
590   /// \brief Conservatively evaluate call by invalidating regions and binding
591   /// a conjured return value.
592   void conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr,
593                             ExplodedNode *Pred, ProgramStateRef State);
594 
595   /// \brief Either inline or process the call conservatively (or both), based
596   /// on DynamicDispatchBifurcation data.
597   void BifurcateCall(const MemRegion *BifurReg,
598                      const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
599                      ExplodedNode *Pred);
600 
601   bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC);
602 
603   /// Models a trivial copy or move constructor or trivial assignment operator
604   /// call with a simple bind.
605   void performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred,
606                           const CallEvent &Call);
607 
608   /// If the value of the given expression is a NonLoc, copy it into a new
609   /// temporary object region, and replace the value of the expression with
610   /// that.
611   ///
612   /// If \p ResultE is provided, the new region will be bound to this expression
613   /// instead of \p E.
614   ProgramStateRef createTemporaryRegionIfNeeded(ProgramStateRef State,
615                                                 const LocationContext *LC,
616                                                 const Expr *E,
617                                                 const Expr *ResultE = nullptr);
618 
619   /// For a DeclStmt or CXXInitCtorInitializer, walk backward in the current CFG
620   /// block to find the constructor expression that directly constructed into
621   /// the storage for this statement. Returns null if the constructor for this
622   /// statement created a temporary object region rather than directly
623   /// constructing into an existing region.
624   const CXXConstructExpr *findDirectConstructorForCurrentCFGElement();
625 
626   /// For a CXXConstructExpr, walk forward in the current CFG block to find the
627   /// CFGElement for the DeclStmt or CXXInitCtorInitializer for which is
628   /// directly constructed by this constructor. Returns None if the current
629   /// constructor expression did not directly construct into an existing
630   /// region.
631   Optional<CFGElement> findElementDirectlyInitializedByCurrentConstructor();
632 
633   /// For a given constructor, look forward in the current CFG block to
634   /// determine the region into which an object will be constructed by \p CE.
635   /// Returns either a field or local variable region if the object will be
636   /// directly constructed in an existing region or a temporary object region
637   /// if not.
638   const MemRegion *getRegionForConstructedObject(const CXXConstructExpr *CE,
639                                                  ExplodedNode *Pred);
640 };
641 
642 /// Traits for storing the call processing policy inside GDM.
643 /// The GDM stores the corresponding CallExpr pointer.
644 // FIXME: This does not use the nice trait macros because it must be accessible
645 // from multiple translation units.
646 struct ReplayWithoutInlining{};
647 template <>
648 struct ProgramStateTrait<ReplayWithoutInlining> :
649   public ProgramStatePartialTrait<const void*> {
650   static void *GDMIndex() { static int index = 0; return &index; }
651 };
652 
653 } // end ento namespace
654 
655 } // end clang namespace
656 
657 #endif
658