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 generate end-of-path
257   /// nodes when the control reaches the end of a function.
258   void processEndOfFunction(NodeBuilderContext& BC,
259                             ExplodedNode *Pred) override;
260 
261   /// Remove dead bindings/symbols before exiting a function.
262   void removeDeadOnEndOfFunction(NodeBuilderContext& BC,
263                                  ExplodedNode *Pred,
264                                  ExplodedNodeSet &Dst);
265 
266   /// Generate the entry node of the callee.
267   void processCallEnter(CallEnter CE, ExplodedNode *Pred) override;
268 
269   /// Generate the sequence of nodes that simulate the call exit and the post
270   /// visit for CallExpr.
271   void processCallExit(ExplodedNode *Pred) override;
272 
273   /// Called by CoreEngine when the analysis worklist has terminated.
274   void processEndWorklist(bool hasWorkRemaining) override;
275 
276   /// evalAssume - Callback function invoked by the ConstraintManager when
277   ///  making assumptions about state values.
278   ProgramStateRef processAssume(ProgramStateRef state, SVal cond,
279                                 bool assumption) override;
280 
281   /// wantsRegionChangeUpdate - Called by ProgramStateManager to determine if a
282   ///  region change should trigger a processRegionChanges update.
283   bool wantsRegionChangeUpdate(ProgramStateRef state) override;
284 
285   /// processRegionChanges - Called by ProgramStateManager whenever a change is made
286   ///  to the store. Used to update checkers that track region values.
287   ProgramStateRef
288   processRegionChanges(ProgramStateRef state,
289                        const InvalidatedSymbols *invalidated,
290                        ArrayRef<const MemRegion *> ExplicitRegions,
291                        ArrayRef<const MemRegion *> Regions,
292                        const CallEvent *Call) override;
293 
294   /// printState - Called by ProgramStateManager to print checker-specific data.
295   void printState(raw_ostream &Out, ProgramStateRef State,
296                   const char *NL, const char *Sep) override;
297 
getStateManager()298   ProgramStateManager& getStateManager() override { return StateMgr; }
299 
getStoreManager()300   StoreManager& getStoreManager() { return StateMgr.getStoreManager(); }
301 
getConstraintManager()302   ConstraintManager& getConstraintManager() {
303     return StateMgr.getConstraintManager();
304   }
305 
306   // FIXME: Remove when we migrate over to just using SValBuilder.
getBasicVals()307   BasicValueFactory& getBasicVals() {
308     return StateMgr.getBasicVals();
309   }
310 
311   // FIXME: Remove when we migrate over to just using ValueManager.
getSymbolManager()312   SymbolManager& getSymbolManager() { return SymMgr; }
getSymbolManager()313   const SymbolManager& getSymbolManager() const { return SymMgr; }
314 
315   // Functions for external checking of whether we have unfinished work
wasBlocksExhausted()316   bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); }
hasEmptyWorkList()317   bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); }
hasWorkRemaining()318   bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); }
319 
getCoreEngine()320   const CoreEngine &getCoreEngine() const { return Engine; }
321 
322 public:
323   /// Visit - Transfer function logic for all statements.  Dispatches to
324   ///  other functions that handle specific kinds of statements.
325   void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst);
326 
327   /// VisitArraySubscriptExpr - Transfer function for array accesses.
328   void VisitLvalArraySubscriptExpr(const ArraySubscriptExpr *Ex,
329                                    ExplodedNode *Pred,
330                                    ExplodedNodeSet &Dst);
331 
332   /// VisitGCCAsmStmt - Transfer function logic for inline asm.
333   void VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred,
334                        ExplodedNodeSet &Dst);
335 
336   /// VisitMSAsmStmt - Transfer function logic for MS inline asm.
337   void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred,
338                       ExplodedNodeSet &Dst);
339 
340   /// VisitBlockExpr - Transfer function logic for BlockExprs.
341   void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred,
342                       ExplodedNodeSet &Dst);
343 
344   /// VisitLambdaExpr - Transfer function logic for LambdaExprs.
345   void VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred,
346                        ExplodedNodeSet &Dst);
347 
348   /// VisitBinaryOperator - Transfer function logic for binary operators.
349   void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred,
350                            ExplodedNodeSet &Dst);
351 
352 
353   /// VisitCall - Transfer function for function calls.
354   void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred,
355                      ExplodedNodeSet &Dst);
356 
357   /// VisitCast - Transfer function logic for all casts (implicit and explicit).
358   void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred,
359                 ExplodedNodeSet &Dst);
360 
361   /// VisitCompoundLiteralExpr - Transfer function logic for compound literals.
362   void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
363                                 ExplodedNode *Pred, ExplodedNodeSet &Dst);
364 
365   /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs.
366   void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D,
367                               ExplodedNode *Pred, ExplodedNodeSet &Dst);
368 
369   /// VisitDeclStmt - Transfer function logic for DeclStmts.
370   void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred,
371                      ExplodedNodeSet &Dst);
372 
373   /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose
374   void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R,
375                         ExplodedNode *Pred, ExplodedNodeSet &Dst);
376 
377   void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred,
378                          ExplodedNodeSet &Dst);
379 
380   /// VisitLogicalExpr - Transfer function logic for '&&', '||'
381   void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred,
382                         ExplodedNodeSet &Dst);
383 
384   /// VisitMemberExpr - Transfer function for member expressions.
385   void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred,
386                            ExplodedNodeSet &Dst);
387 
388   /// Transfer function logic for ObjCAtSynchronizedStmts.
389   void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S,
390                                    ExplodedNode *Pred, ExplodedNodeSet &Dst);
391 
392   /// Transfer function logic for computing the lvalue of an Objective-C ivar.
393   void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred,
394                                 ExplodedNodeSet &Dst);
395 
396   /// VisitObjCForCollectionStmt - Transfer function logic for
397   ///  ObjCForCollectionStmt.
398   void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S,
399                                   ExplodedNode *Pred, ExplodedNodeSet &Dst);
400 
401   void VisitObjCMessage(const ObjCMessageExpr *ME, ExplodedNode *Pred,
402                         ExplodedNodeSet &Dst);
403 
404   /// VisitReturnStmt - Transfer function logic for return statements.
405   void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred,
406                        ExplodedNodeSet &Dst);
407 
408   /// VisitOffsetOfExpr - Transfer function for offsetof.
409   void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred,
410                          ExplodedNodeSet &Dst);
411 
412   /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
413   void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex,
414                               ExplodedNode *Pred, ExplodedNodeSet &Dst);
415 
416   /// VisitUnaryOperator - Transfer function logic for unary operators.
417   void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred,
418                           ExplodedNodeSet &Dst);
419 
420   /// Handle ++ and -- (both pre- and post-increment).
421   void VisitIncrementDecrementOperator(const UnaryOperator* U,
422                                        ExplodedNode *Pred,
423                                        ExplodedNodeSet &Dst);
424 
425   void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE,
426                                  ExplodedNodeSet &PreVisit,
427                                  ExplodedNodeSet &Dst);
428 
429   void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred,
430                          ExplodedNodeSet &Dst);
431 
432   void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
433                         ExplodedNodeSet & Dst);
434 
435   void VisitCXXConstructExpr(const CXXConstructExpr *E, ExplodedNode *Pred,
436                              ExplodedNodeSet &Dst);
437 
438   void VisitCXXDestructor(QualType ObjectType, const MemRegion *Dest,
439                           const Stmt *S, bool IsBaseDtor,
440                           ExplodedNode *Pred, ExplodedNodeSet &Dst);
441 
442   void VisitCXXNewAllocatorCall(const CXXNewExpr *CNE,
443                                 ExplodedNode *Pred,
444                                 ExplodedNodeSet &Dst);
445 
446   void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
447                        ExplodedNodeSet &Dst);
448 
449   void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred,
450                           ExplodedNodeSet &Dst);
451 
452   /// Create a C++ temporary object for an rvalue.
453   void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME,
454                                 ExplodedNode *Pred,
455                                 ExplodedNodeSet &Dst);
456 
457   /// evalEagerlyAssumeBinOpBifurcation - Given the nodes in 'Src', eagerly assume symbolic
458   ///  expressions of the form 'x != 0' and generate new nodes (stored in Dst)
459   ///  with those assumptions.
460   void evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst, ExplodedNodeSet &Src,
461                          const Expr *Ex);
462 
463   std::pair<const ProgramPointTag *, const ProgramPointTag*>
464     geteagerlyAssumeBinOpBifurcationTags();
465 
evalMinus(SVal X)466   SVal evalMinus(SVal X) {
467     return X.isValid() ? svalBuilder.evalMinus(X.castAs<NonLoc>()) : X;
468   }
469 
evalComplement(SVal X)470   SVal evalComplement(SVal X) {
471     return X.isValid() ? svalBuilder.evalComplement(X.castAs<NonLoc>()) : X;
472   }
473 
474 public:
475 
evalBinOp(ProgramStateRef state,BinaryOperator::Opcode op,NonLoc L,NonLoc R,QualType T)476   SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
477                  NonLoc L, NonLoc R, QualType T) {
478     return svalBuilder.evalBinOpNN(state, op, L, R, T);
479   }
480 
evalBinOp(ProgramStateRef state,BinaryOperator::Opcode op,NonLoc L,SVal R,QualType T)481   SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
482                  NonLoc L, SVal R, QualType T) {
483     return R.isValid() ? svalBuilder.evalBinOpNN(state, op, L,
484                                                  R.castAs<NonLoc>(), T) : R;
485   }
486 
evalBinOp(ProgramStateRef ST,BinaryOperator::Opcode Op,SVal LHS,SVal RHS,QualType T)487   SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op,
488                  SVal LHS, SVal RHS, QualType T) {
489     return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T);
490   }
491 
492 protected:
493   /// evalBind - Handle the semantics of binding a value to a specific location.
494   ///  This method is used by evalStore, VisitDeclStmt, and others.
495   void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred,
496                 SVal location, SVal Val, bool atDeclInit = false,
497                 const ProgramPoint *PP = nullptr);
498 
499   /// Call PointerEscape callback when a value escapes as a result of bind.
500   ProgramStateRef processPointerEscapedOnBind(ProgramStateRef State,
501                                               SVal Loc, SVal Val) override;
502   /// Call PointerEscape callback when a value escapes as a result of
503   /// region invalidation.
504   /// \param[in] ITraits Specifies invalidation traits for regions/symbols.
505   ProgramStateRef notifyCheckersOfPointerEscape(
506                            ProgramStateRef State,
507                            const InvalidatedSymbols *Invalidated,
508                            ArrayRef<const MemRegion *> ExplicitRegions,
509                            ArrayRef<const MemRegion *> Regions,
510                            const CallEvent *Call,
511                            RegionAndSymbolInvalidationTraits &ITraits) override;
512 
513 public:
514   // FIXME: 'tag' should be removed, and a LocationContext should be used
515   // instead.
516   // FIXME: Comment on the meaning of the arguments, when 'St' may not
517   // be the same as Pred->state, and when 'location' may not be the
518   // same as state->getLValue(Ex).
519   /// Simulate a read of the result of Ex.
520   void evalLoad(ExplodedNodeSet &Dst,
521                 const Expr *NodeEx,  /* Eventually will be a CFGStmt */
522                 const Expr *BoundExpr,
523                 ExplodedNode *Pred,
524                 ProgramStateRef St,
525                 SVal location,
526                 const ProgramPointTag *tag = nullptr,
527                 QualType LoadTy = QualType());
528 
529   // FIXME: 'tag' should be removed, and a LocationContext should be used
530   // instead.
531   void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE,
532                  ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val,
533                  const ProgramPointTag *tag = nullptr);
534 
535   /// \brief Create a new state in which the call return value is binded to the
536   /// call origin expression.
537   ProgramStateRef bindReturnValue(const CallEvent &Call,
538                                   const LocationContext *LCtx,
539                                   ProgramStateRef State);
540 
541   /// Evaluate a call, running pre- and post-call checks and allowing checkers
542   /// to be responsible for handling the evaluation of the call itself.
543   void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred,
544                 const CallEvent &Call);
545 
546   /// \brief Default implementation of call evaluation.
547   void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred,
548                        const CallEvent &Call);
549 private:
550   void evalLoadCommon(ExplodedNodeSet &Dst,
551                       const Expr *NodeEx,  /* Eventually will be a CFGStmt */
552                       const Expr *BoundEx,
553                       ExplodedNode *Pred,
554                       ProgramStateRef St,
555                       SVal location,
556                       const ProgramPointTag *tag,
557                       QualType LoadTy);
558 
559   // FIXME: 'tag' should be removed, and a LocationContext should be used
560   // instead.
561   void evalLocation(ExplodedNodeSet &Dst,
562                     const Stmt *NodeEx, /* This will eventually be a CFGStmt */
563                     const Stmt *BoundEx,
564                     ExplodedNode *Pred,
565                     ProgramStateRef St, SVal location,
566                     const ProgramPointTag *tag, bool isLoad);
567 
568   /// Count the stack depth and determine if the call is recursive.
569   void examineStackFrames(const Decl *D, const LocationContext *LCtx,
570                           bool &IsRecursive, unsigned &StackDepth);
571 
572   /// Checks our policies and decides weither the given call should be inlined.
573   bool shouldInlineCall(const CallEvent &Call, const Decl *D,
574                         const ExplodedNode *Pred);
575 
576   bool inlineCall(const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
577                   ExplodedNode *Pred, ProgramStateRef State);
578 
579   /// \brief Conservatively evaluate call by invalidating regions and binding
580   /// a conjured return value.
581   void conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr,
582                             ExplodedNode *Pred, ProgramStateRef State);
583 
584   /// \brief Either inline or process the call conservatively (or both), based
585   /// on DynamicDispatchBifurcation data.
586   void BifurcateCall(const MemRegion *BifurReg,
587                      const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
588                      ExplodedNode *Pred);
589 
590   bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC);
591 
592   /// Models a trivial copy or move constructor or trivial assignment operator
593   /// call with a simple bind.
594   void performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred,
595                           const CallEvent &Call);
596 
597   /// If the value of the given expression is a NonLoc, copy it into a new
598   /// temporary object region, and replace the value of the expression with
599   /// that.
600   ///
601   /// If \p ResultE is provided, the new region will be bound to this expression
602   /// instead of \p E.
603   ProgramStateRef createTemporaryRegionIfNeeded(ProgramStateRef State,
604                                                 const LocationContext *LC,
605                                                 const Expr *E,
606                                                 const Expr *ResultE = nullptr);
607 
608   /// For a DeclStmt or CXXInitCtorInitializer, walk backward in the current CFG
609   /// block to find the constructor expression that directly constructed into
610   /// the storage for this statement. Returns null if the constructor for this
611   /// statement created a temporary object region rather than directly
612   /// constructing into an existing region.
613   const CXXConstructExpr *findDirectConstructorForCurrentCFGElement();
614 
615   /// For a CXXConstructExpr, walk forward in the current CFG block to find the
616   /// CFGElement for the DeclStmt or CXXInitCtorInitializer for which is
617   /// directly constructed by this constructor. Returns None if the current
618   /// constructor expression did not directly construct into an existing
619   /// region.
620   Optional<CFGElement> findElementDirectlyInitializedByCurrentConstructor();
621 
622   /// For a given constructor, look forward in the current CFG block to
623   /// determine the region into which an object will be constructed by \p CE.
624   /// Returns either a field or local variable region if the object will be
625   /// directly constructed in an existing region or a temporary object region
626   /// if not.
627   const MemRegion *getRegionForConstructedObject(const CXXConstructExpr *CE,
628                                                  ExplodedNode *Pred);
629 };
630 
631 /// Traits for storing the call processing policy inside GDM.
632 /// The GDM stores the corresponding CallExpr pointer.
633 // FIXME: This does not use the nice trait macros because it must be accessible
634 // from multiple translation units.
635 struct ReplayWithoutInlining{};
636 template <>
637 struct ProgramStateTrait<ReplayWithoutInlining> :
638   public ProgramStatePartialTrait<const void*> {
639   static void *GDMIndex() { static int index = 0; return &index; }
640 };
641 
642 } // end ento namespace
643 
644 } // end clang namespace
645 
646 #endif
647