text: //===- ExprEngine.h - Path-Sensitive Expression-Level Dataflow --*- C++ -*-===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  //  This file defines a meta-engine for path-sensitive dataflow analysis that
  //  is built on CoreEngine, but provides the boilerplate to execute transfer
  //  functions and build the ExplodedGraph at the expression level.
  //
  //===----------------------------------------------------------------------===//
  
  #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
  #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
  
  #include "clang/AST/Expr.h"
  #include "clang/AST/Type.h"
  #include "clang/Analysis/CFG.h"
  #include "clang/Analysis/DomainSpecific/ObjCNoReturn.h"
  #include "clang/Analysis/ProgramPoint.h"
  #include "clang/Basic/LLVM.h"
  #include "clang/StaticAnalyzer/Core/CheckerManager.h"
  #include "clang/StaticAnalyzer/Core/BugReporter/BugReporter.h"
  #include "clang/StaticAnalyzer/Core/BugReporter/BugReporterVisitors.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/AnalysisManager.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/CoreEngine.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/FunctionSummary.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramStateTrait.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
  #include "clang/StaticAnalyzer/Core/PathSensitive/WorkList.h"
  #include "llvm/ADT/ArrayRef.h"
  #include <cassert>
  #include <utility>
  
  namespace clang {
  
  class AnalysisDeclContextManager;
  class AnalyzerOptions;
  class ASTContext;
  class CFGBlock;
  class CFGElement;
  class ConstructionContext;
  class CXXBindTemporaryExpr;
  class CXXCatchStmt;
  class CXXConstructExpr;
  class CXXDeleteExpr;
  class CXXNewExpr;
  class CXXThisExpr;
  class Decl;
  class DeclStmt;
  class GCCAsmStmt;
  class LambdaExpr;
  class LocationContext;
  class MaterializeTemporaryExpr;
  class MSAsmStmt;
  class NamedDecl;
  class ObjCAtSynchronizedStmt;
  class ObjCForCollectionStmt;
  class ObjCIvarRefExpr;
  class ObjCMessageExpr;
  class ReturnStmt;
  class Stmt;
  
  namespace cross_tu {
  
  class CrossTranslationUnitContext;
  
  } // namespace cross_tu
  
  namespace ento {
  
  class AnalysisManager;
  class BasicValueFactory;
  class BlockCounter;
  class BranchNodeBuilder;
  class CallEvent;
  class CheckerManager;
  class ConstraintManager;
  class CXXTempObjectRegion;
  class EndOfFunctionNodeBuilder;
  class ExplodedNodeSet;
  class ExplodedNode;
  class IndirectGotoNodeBuilder;
  class MemRegion;
  struct NodeBuilderContext;
  class NodeBuilderWithSinks;
  class ProgramState;
  class ProgramStateManager;
  class RegionAndSymbolInvalidationTraits;
  class SymbolManager;
  class SwitchNodeBuilder;
  
  /// Hints for figuring out of a call should be inlined during evalCall().
  struct EvalCallOptions {
    /// This call is a constructor or a destructor for which we do not currently
    /// compute the this-region correctly.
    bool IsCtorOrDtorWithImproperlyModeledTargetRegion = false;
  
    /// This call is a constructor or a destructor for a single element within
    /// an array, a part of array construction or destruction.
    bool IsArrayCtorOrDtor = false;
  
    /// This call is a constructor or a destructor of a temporary value.
    bool IsTemporaryCtorOrDtor = false;
  
    /// This call is a constructor for a temporary that is lifetime-extended
    /// by binding it to a reference-type field within an aggregate,
    /// for example 'A { const C &c; }; A a = { C() };'
    bool IsTemporaryLifetimeExtendedViaAggregate = false;
  
    /// This call is a pre-C++17 elidable constructor that we failed to elide
    /// because we failed to compute the target region into which
    /// this constructor would have been ultimately elided. Analysis that
    /// we perform in this case is still correct but it behaves differently,
    /// as if copy elision is disabled.
    bool IsElidableCtorThatHasNotBeenElided = false;
  
    EvalCallOptions() {}
  };
  
  class ExprEngine {
    void anchor();
  
  public:
    /// The modes of inlining, which override the default analysis-wide settings.
    enum InliningModes {
      /// Follow the default settings for inlining callees.
      Inline_Regular = 0,
  
      /// Do minimal inlining of callees.
      Inline_Minimal = 0x1
    };
  
  private:
    cross_tu::CrossTranslationUnitContext &CTU;
  
    AnalysisManager &AMgr;
  
    AnalysisDeclContextManager &AnalysisDeclContexts;
  
    CoreEngine Engine;
  
    /// G - the simulation graph.
    ExplodedGraph &G;
  
    /// StateMgr - Object that manages the data for all created states.
    ProgramStateManager StateMgr;
  
    /// SymMgr - Object that manages the symbol information.
    SymbolManager &SymMgr;
  
    /// MRMgr - MemRegionManager object that creates memory regions.
    MemRegionManager &MRMgr;
  
    /// svalBuilder - SValBuilder object that creates SVals from expressions.
    SValBuilder &svalBuilder;
  
    unsigned int currStmtIdx = 0;
    const NodeBuilderContext *currBldrCtx = nullptr;
  
    /// Helper object to determine if an Objective-C message expression
    /// implicitly never returns.
    ObjCNoReturn ObjCNoRet;
  
    /// The BugReporter associated with this engine.  It is important that
    /// this object be placed at the very end of member variables so that its
    /// destructor is called before the rest of the ExprEngine is destroyed.
    PathSensitiveBugReporter BR;
  
    /// The functions which have been analyzed through inlining. This is owned by
    /// AnalysisConsumer. It can be null.
    SetOfConstDecls *VisitedCallees;
  
    /// The flag, which specifies the mode of inlining for the engine.
    InliningModes HowToInline;
  
  public:
    ExprEngine(cross_tu::CrossTranslationUnitContext &CTU, AnalysisManager &mgr,
               SetOfConstDecls *VisitedCalleesIn,
               FunctionSummariesTy *FS, InliningModes HowToInlineIn);
  
    virtual ~ExprEngine() = default;
  
    /// Returns true if there is still simulation state on the worklist.
    bool ExecuteWorkList(const LocationContext *L, unsigned Steps = 150000) {
      return Engine.ExecuteWorkList(L, Steps, nullptr);
    }
  
    /// Execute the work list with an initial state. Nodes that reaches the exit
    /// of the function are added into the Dst set, which represent the exit
    /// state of the function call. Returns true if there is still simulation
    /// state on the worklist.
    bool ExecuteWorkListWithInitialState(const LocationContext *L, unsigned Steps,
                                         ProgramStateRef InitState,
                                         ExplodedNodeSet &Dst) {
      return Engine.ExecuteWorkListWithInitialState(L, Steps, InitState, Dst);
    }
  
    /// getContext - Return the ASTContext associated with this analysis.
    ASTContext &getContext() const { return AMgr.getASTContext(); }
  
    AnalysisManager &getAnalysisManager() { return AMgr; }
  
    AnalysisDeclContextManager &getAnalysisDeclContextManager() {
      return AMgr.getAnalysisDeclContextManager();
    }
  
    CheckerManager &getCheckerManager() const {
      return *AMgr.getCheckerManager();
    }
  
    SValBuilder &getSValBuilder() { return svalBuilder; }
  
    BugReporter &getBugReporter() { return BR; }
  
    cross_tu::CrossTranslationUnitContext *
    getCrossTranslationUnitContext() {
      return &CTU;
    }
  
    const NodeBuilderContext &getBuilderContext() {
      assert(currBldrCtx);
      return *currBldrCtx;
    }
  
    const Stmt *getStmt() const;
  
    void GenerateAutoTransition(ExplodedNode *N);
    void enqueueEndOfPath(ExplodedNodeSet &S);
    void GenerateCallExitNode(ExplodedNode *N);
  
  
    /// Dump graph to the specified filename.
    /// If filename is empty, generate a temporary one.
    /// \return The filename the graph is written into.
    std::string DumpGraph(bool trim = false, StringRef Filename="");
  
    /// Dump the graph consisting of the given nodes to a specified filename.
    /// Generate a temporary filename if it's not provided.
    /// \return The filename the graph is written into.
    std::string DumpGraph(ArrayRef<const ExplodedNode *> Nodes,
                          StringRef Filename = "");
  
    /// Visualize the ExplodedGraph created by executing the simulation.
    void ViewGraph(bool trim = false);
  
    /// Visualize a trimmed ExplodedGraph that only contains paths to the given
    /// nodes.
    void ViewGraph(ArrayRef<const ExplodedNode *> Nodes);
  
    /// getInitialState - Return the initial state used for the root vertex
    ///  in the ExplodedGraph.
    ProgramStateRef getInitialState(const LocationContext *InitLoc);
  
    ExplodedGraph &getGraph() { return G; }
    const ExplodedGraph &getGraph() const { return G; }
  
    /// Run the analyzer's garbage collection - remove dead symbols and
    /// bindings from the state.
    ///
    /// Checkers can participate in this process with two callbacks:
    /// \c checkLiveSymbols and \c checkDeadSymbols. See the CheckerDocumentation
    /// class for more information.
    ///
    /// \param Node The predecessor node, from which the processing should start.
    /// \param Out The returned set of output nodes.
    /// \param ReferenceStmt The statement which is about to be processed.
    ///        Everything needed for this statement should be considered live.
    ///        A null statement means that everything in child LocationContexts
    ///        is dead.
    /// \param LC The location context of the \p ReferenceStmt. A null location
    ///        context means that we have reached the end of analysis and that
    ///        all statements and local variables should be considered dead.
    /// \param DiagnosticStmt Used as a location for any warnings that should
    ///        occur while removing the dead (e.g. leaks). By default, the
    ///        \p ReferenceStmt is used.
    /// \param K Denotes whether this is a pre- or post-statement purge. This
    ///        must only be ProgramPoint::PostStmtPurgeDeadSymbolsKind if an
    ///        entire location context is being cleared, in which case the
    ///        \p ReferenceStmt must either be a ReturnStmt or \c NULL. Otherwise,
    ///        it must be ProgramPoint::PreStmtPurgeDeadSymbolsKind (the default)
    ///        and \p ReferenceStmt must be valid (non-null).
    void removeDead(ExplodedNode *Node, ExplodedNodeSet &Out,
              const Stmt *ReferenceStmt, const LocationContext *LC,
              const Stmt *DiagnosticStmt = nullptr,
              ProgramPoint::Kind K = ProgramPoint::PreStmtPurgeDeadSymbolsKind);
  
    /// processCFGElement - Called by CoreEngine. Used to generate new successor
    ///  nodes by processing the 'effects' of a CFG element.
    void processCFGElement(const CFGElement E, ExplodedNode *Pred,
                           unsigned StmtIdx, NodeBuilderContext *Ctx);
  
    void ProcessStmt(const Stmt *S, ExplodedNode *Pred);
  
    void ProcessLoopExit(const Stmt* S, ExplodedNode *Pred);
  
    void ProcessInitializer(const CFGInitializer I, ExplodedNode *Pred);
  
    void ProcessImplicitDtor(const CFGImplicitDtor D, ExplodedNode *Pred);
  
    void ProcessNewAllocator(const CXXNewExpr *NE, ExplodedNode *Pred);
  
    void ProcessAutomaticObjDtor(const CFGAutomaticObjDtor D,
                                 ExplodedNode *Pred, ExplodedNodeSet &Dst);
    void ProcessDeleteDtor(const CFGDeleteDtor D,
                           ExplodedNode *Pred, ExplodedNodeSet &Dst);
    void ProcessBaseDtor(const CFGBaseDtor D,
                         ExplodedNode *Pred, ExplodedNodeSet &Dst);
    void ProcessMemberDtor(const CFGMemberDtor D,
                           ExplodedNode *Pred, ExplodedNodeSet &Dst);
    void ProcessTemporaryDtor(const CFGTemporaryDtor D,
                              ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    /// Called by CoreEngine when processing the entrance of a CFGBlock.
    void processCFGBlockEntrance(const BlockEdge &L,
                                 NodeBuilderWithSinks &nodeBuilder,
                                 ExplodedNode *Pred);
  
    /// ProcessBranch - Called by CoreEngine.  Used to generate successor
    ///  nodes by processing the 'effects' of a branch condition.
    void processBranch(const Stmt *Condition,
                       NodeBuilderContext& BuilderCtx,
                       ExplodedNode *Pred,
                       ExplodedNodeSet &Dst,
                       const CFGBlock *DstT,
                       const CFGBlock *DstF);
  
    /// Called by CoreEngine.
    /// Used to generate successor nodes for temporary destructors depending
    /// on whether the corresponding constructor was visited.
    void processCleanupTemporaryBranch(const CXXBindTemporaryExpr *BTE,
                                       NodeBuilderContext &BldCtx,
                                       ExplodedNode *Pred, ExplodedNodeSet &Dst,
                                       const CFGBlock *DstT,
                                       const CFGBlock *DstF);
  
    /// Called by CoreEngine.  Used to processing branching behavior
    /// at static initializers.
    void processStaticInitializer(const DeclStmt *DS,
                                  NodeBuilderContext& BuilderCtx,
                                  ExplodedNode *Pred,
                                  ExplodedNodeSet &Dst,
                                  const CFGBlock *DstT,
                                  const CFGBlock *DstF);
  
    /// processIndirectGoto - Called by CoreEngine.  Used to generate successor
    ///  nodes by processing the 'effects' of a computed goto jump.
    void processIndirectGoto(IndirectGotoNodeBuilder& builder);
  
    /// ProcessSwitch - Called by CoreEngine.  Used to generate successor
    ///  nodes by processing the 'effects' of a switch statement.
    void processSwitch(SwitchNodeBuilder& builder);
  
    /// Called by CoreEngine.  Used to notify checkers that processing a
    /// function has begun. Called for both inlined and and top-level functions.
    void processBeginOfFunction(NodeBuilderContext &BC,
                                ExplodedNode *Pred, ExplodedNodeSet &Dst,
                                const BlockEdge &L);
  
    /// Called by CoreEngine.  Used to notify checkers that processing a
    /// function has ended. Called for both inlined and and top-level functions.
    void processEndOfFunction(NodeBuilderContext& BC,
                              ExplodedNode *Pred,
                              const ReturnStmt *RS = nullptr);
  
    /// Remove dead bindings/symbols before exiting a function.
    void removeDeadOnEndOfFunction(NodeBuilderContext& BC,
                                   ExplodedNode *Pred,
                                   ExplodedNodeSet &Dst);
  
    /// Generate the entry node of the callee.
    void processCallEnter(NodeBuilderContext& BC, CallEnter CE,
                          ExplodedNode *Pred);
  
    /// Generate the sequence of nodes that simulate the call exit and the post
    /// visit for CallExpr.
    void processCallExit(ExplodedNode *Pred);
  
    /// Called by CoreEngine when the analysis worklist has terminated.
    void processEndWorklist();
  
    /// evalAssume - Callback function invoked by the ConstraintManager when
    ///  making assumptions about state values.
    ProgramStateRef processAssume(ProgramStateRef state, SVal cond,
                                  bool assumption);
  
    /// processRegionChanges - Called by ProgramStateManager whenever a change is made
    ///  to the store. Used to update checkers that track region values.
    ProgramStateRef
    processRegionChanges(ProgramStateRef state,
                         const InvalidatedSymbols *invalidated,
                         ArrayRef<const MemRegion *> ExplicitRegions,
                         ArrayRef<const MemRegion *> Regions,
                         const LocationContext *LCtx,
                         const CallEvent *Call);
  
    inline ProgramStateRef
    processRegionChange(ProgramStateRef state,
                        const MemRegion* MR,
                        const LocationContext *LCtx) {
      return processRegionChanges(state, nullptr, MR, MR, LCtx, nullptr);
    }
  
    /// printJson - Called by ProgramStateManager to print checker-specific data.
    void printJson(raw_ostream &Out, ProgramStateRef State,
                   const LocationContext *LCtx, const char *NL,
                   unsigned int Space, bool IsDot) const;
  
    ProgramStateManager &getStateManager() { return StateMgr; }
  
    StoreManager &getStoreManager() { return StateMgr.getStoreManager(); }
  
    ConstraintManager &getConstraintManager() {
      return StateMgr.getConstraintManager();
    }
  
    // FIXME: Remove when we migrate over to just using SValBuilder.
    BasicValueFactory &getBasicVals() {
      return StateMgr.getBasicVals();
    }
  
    SymbolManager &getSymbolManager() { return SymMgr; }
    MemRegionManager &getRegionManager() { return MRMgr; }
  
    NoteTag::Factory &getNoteTags() { return Engine.getNoteTags(); }
  
  
    // Functions for external checking of whether we have unfinished work
    bool wasBlocksExhausted() const { return Engine.wasBlocksExhausted(); }
    bool hasEmptyWorkList() const { return !Engine.getWorkList()->hasWork(); }
    bool hasWorkRemaining() const { return Engine.hasWorkRemaining(); }
  
    const CoreEngine &getCoreEngine() const { return Engine; }
  
  public:
    /// Visit - Transfer function logic for all statements.  Dispatches to
    ///  other functions that handle specific kinds of statements.
    void Visit(const Stmt *S, ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    /// VisitArraySubscriptExpr - Transfer function for array accesses.
    void VisitArraySubscriptExpr(const ArraySubscriptExpr *Ex,
                                 ExplodedNode *Pred,
                                 ExplodedNodeSet &Dst);
  
    /// VisitGCCAsmStmt - Transfer function logic for inline asm.
    void VisitGCCAsmStmt(const GCCAsmStmt *A, ExplodedNode *Pred,
                         ExplodedNodeSet &Dst);
  
    /// VisitMSAsmStmt - Transfer function logic for MS inline asm.
    void VisitMSAsmStmt(const MSAsmStmt *A, ExplodedNode *Pred,
                        ExplodedNodeSet &Dst);
  
    /// VisitBlockExpr - Transfer function logic for BlockExprs.
    void VisitBlockExpr(const BlockExpr *BE, ExplodedNode *Pred,
                        ExplodedNodeSet &Dst);
  
    /// VisitLambdaExpr - Transfer function logic for LambdaExprs.
    void VisitLambdaExpr(const LambdaExpr *LE, ExplodedNode *Pred,
                         ExplodedNodeSet &Dst);
  
    /// VisitBinaryOperator - Transfer function logic for binary operators.
    void VisitBinaryOperator(const BinaryOperator* B, ExplodedNode *Pred,
                             ExplodedNodeSet &Dst);
  
  
    /// VisitCall - Transfer function for function calls.
    void VisitCallExpr(const CallExpr *CE, ExplodedNode *Pred,
                       ExplodedNodeSet &Dst);
  
    /// VisitCast - Transfer function logic for all casts (implicit and explicit).
    void VisitCast(const CastExpr *CastE, const Expr *Ex, ExplodedNode *Pred,
                   ExplodedNodeSet &Dst);
  
    /// VisitCompoundLiteralExpr - Transfer function logic for compound literals.
    void VisitCompoundLiteralExpr(const CompoundLiteralExpr *CL,
                                  ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    /// Transfer function logic for DeclRefExprs and BlockDeclRefExprs.
    void VisitCommonDeclRefExpr(const Expr *DR, const NamedDecl *D,
                                ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    /// VisitDeclStmt - Transfer function logic for DeclStmts.
    void VisitDeclStmt(const DeclStmt *DS, ExplodedNode *Pred,
                       ExplodedNodeSet &Dst);
  
    /// VisitGuardedExpr - Transfer function logic for ?, __builtin_choose
    void VisitGuardedExpr(const Expr *Ex, const Expr *L, const Expr *R,
                          ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    void VisitInitListExpr(const InitListExpr *E, ExplodedNode *Pred,
                           ExplodedNodeSet &Dst);
  
    /// VisitLogicalExpr - Transfer function logic for '&&', '||'
    void VisitLogicalExpr(const BinaryOperator* B, ExplodedNode *Pred,
                          ExplodedNodeSet &Dst);
  
    /// VisitMemberExpr - Transfer function for member expressions.
    void VisitMemberExpr(const MemberExpr *M, ExplodedNode *Pred,
                         ExplodedNodeSet &Dst);
  
    /// VisitAtomicExpr - Transfer function for builtin atomic expressions
    void VisitAtomicExpr(const AtomicExpr *E, ExplodedNode *Pred,
                         ExplodedNodeSet &Dst);
  
    /// Transfer function logic for ObjCAtSynchronizedStmts.
    void VisitObjCAtSynchronizedStmt(const ObjCAtSynchronizedStmt *S,
                                     ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    /// Transfer function logic for computing the lvalue of an Objective-C ivar.
    void VisitLvalObjCIvarRefExpr(const ObjCIvarRefExpr *DR, ExplodedNode *Pred,
                                  ExplodedNodeSet &Dst);
  
    /// VisitObjCForCollectionStmt - Transfer function logic for
    ///  ObjCForCollectionStmt.
    void VisitObjCForCollectionStmt(const ObjCForCollectionStmt *S,
                                    ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    void VisitObjCMessage(const ObjCMessageExpr *ME, ExplodedNode *Pred,
                          ExplodedNodeSet &Dst);
  
    /// VisitReturnStmt - Transfer function logic for return statements.
    void VisitReturnStmt(const ReturnStmt *R, ExplodedNode *Pred,
                         ExplodedNodeSet &Dst);
  
    /// VisitOffsetOfExpr - Transfer function for offsetof.
    void VisitOffsetOfExpr(const OffsetOfExpr *Ex, ExplodedNode *Pred,
                           ExplodedNodeSet &Dst);
  
    /// VisitUnaryExprOrTypeTraitExpr - Transfer function for sizeof.
    void VisitUnaryExprOrTypeTraitExpr(const UnaryExprOrTypeTraitExpr *Ex,
                                       ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    /// VisitUnaryOperator - Transfer function logic for unary operators.
    void VisitUnaryOperator(const UnaryOperator* B, ExplodedNode *Pred,
                            ExplodedNodeSet &Dst);
  
    /// Handle ++ and -- (both pre- and post-increment).
    void VisitIncrementDecrementOperator(const UnaryOperator* U,
                                         ExplodedNode *Pred,
                                         ExplodedNodeSet &Dst);
  
    void VisitCXXBindTemporaryExpr(const CXXBindTemporaryExpr *BTE,
                                   ExplodedNodeSet &PreVisit,
                                   ExplodedNodeSet &Dst);
  
    void VisitCXXCatchStmt(const CXXCatchStmt *CS, ExplodedNode *Pred,
                           ExplodedNodeSet &Dst);
  
    void VisitCXXThisExpr(const CXXThisExpr *TE, ExplodedNode *Pred,
                          ExplodedNodeSet & Dst);
  
    void VisitCXXConstructExpr(const CXXConstructExpr *E, ExplodedNode *Pred,
                               ExplodedNodeSet &Dst);
  
    void VisitCXXInheritedCtorInitExpr(const CXXInheritedCtorInitExpr *E,
                                       ExplodedNode *Pred, ExplodedNodeSet &Dst);
  
    void VisitCXXDestructor(QualType ObjectType, const MemRegion *Dest,
                            const Stmt *S, bool IsBaseDtor,
                            ExplodedNode *Pred, ExplodedNodeSet &Dst,
                            EvalCallOptions &Options);
  
    void VisitCXXNewAllocatorCall(const CXXNewExpr *CNE,
                                  ExplodedNode *Pred,
                                  ExplodedNodeSet &Dst);
  
    void VisitCXXNewExpr(const CXXNewExpr *CNE, ExplodedNode *Pred,
                         ExplodedNodeSet &Dst);
  
    void VisitCXXDeleteExpr(const CXXDeleteExpr *CDE, ExplodedNode *Pred,
                            ExplodedNodeSet &Dst);
  
    /// Create a C++ temporary object for an rvalue.
    void CreateCXXTemporaryObject(const MaterializeTemporaryExpr *ME,
                                  ExplodedNode *Pred,
                                  ExplodedNodeSet &Dst);
  
    /// evalEagerlyAssumeBinOpBifurcation - Given the nodes in 'Src', eagerly assume symbolic
    ///  expressions of the form 'x != 0' and generate new nodes (stored in Dst)
    ///  with those assumptions.
    void evalEagerlyAssumeBinOpBifurcation(ExplodedNodeSet &Dst, ExplodedNodeSet &Src,
                           const Expr *Ex);
  
    static std::pair<const ProgramPointTag *, const ProgramPointTag *>
      geteagerlyAssumeBinOpBifurcationTags();
  
    SVal evalMinus(SVal X) {
      return X.isValid() ? svalBuilder.evalMinus(X.castAs<NonLoc>()) : X;
    }
  
    SVal evalComplement(SVal X) {
      return X.isValid() ? svalBuilder.evalComplement(X.castAs<NonLoc>()) : X;
    }
  
    ProgramStateRef handleLValueBitCast(ProgramStateRef state, const Expr *Ex,
                                        const LocationContext *LCtx, QualType T,
                                        QualType ExTy, const CastExpr *CastE,
                                        StmtNodeBuilder &Bldr,
                                        ExplodedNode *Pred);
  
    ProgramStateRef handleLVectorSplat(ProgramStateRef state,
                                       const LocationContext *LCtx,
                                       const CastExpr *CastE,
                                       StmtNodeBuilder &Bldr,
                                       ExplodedNode *Pred);
  
    void handleUOExtension(ExplodedNodeSet::iterator I,
                           const UnaryOperator* U,
                           StmtNodeBuilder &Bldr);
  
  public:
    SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
                   NonLoc L, NonLoc R, QualType T) {
      return svalBuilder.evalBinOpNN(state, op, L, R, T);
    }
  
    SVal evalBinOp(ProgramStateRef state, BinaryOperator::Opcode op,
                   NonLoc L, SVal R, QualType T) {
      return R.isValid() ? svalBuilder.evalBinOpNN(state, op, L,
                                                   R.castAs<NonLoc>(), T) : R;
    }
  
    SVal evalBinOp(ProgramStateRef ST, BinaryOperator::Opcode Op,
                   SVal LHS, SVal RHS, QualType T) {
      return svalBuilder.evalBinOp(ST, Op, LHS, RHS, T);
    }
  
    /// By looking at a certain item that may be potentially part of an object's
    /// ConstructionContext, retrieve such object's location. A particular
    /// statement can be transparently passed as \p Item in most cases.
    static Optional<SVal>
    getObjectUnderConstruction(ProgramStateRef State,
                               const ConstructionContextItem &Item,
                               const LocationContext *LC);
  
    /// Call PointerEscape callback when a value escapes as a result of bind.
    ProgramStateRef processPointerEscapedOnBind(
        ProgramStateRef State, ArrayRef<std::pair<SVal, SVal>> LocAndVals,
        const LocationContext *LCtx, PointerEscapeKind Kind,
        const CallEvent *Call);
  
    /// Call PointerEscape callback when a value escapes as a result of
    /// region invalidation.
    /// \param[in] ITraits Specifies invalidation traits for regions/symbols.
    ProgramStateRef notifyCheckersOfPointerEscape(
                             ProgramStateRef State,
                             const InvalidatedSymbols *Invalidated,
                             ArrayRef<const MemRegion *> ExplicitRegions,
                             const CallEvent *Call,
                             RegionAndSymbolInvalidationTraits &ITraits);
  
  private:
    /// evalBind - Handle the semantics of binding a value to a specific location.
    ///  This method is used by evalStore, VisitDeclStmt, and others.
    void evalBind(ExplodedNodeSet &Dst, const Stmt *StoreE, ExplodedNode *Pred,
                  SVal location, SVal Val, bool atDeclInit = false,
                  const ProgramPoint *PP = nullptr);
  
    ProgramStateRef
    processPointerEscapedOnBind(ProgramStateRef State,
                                SVal Loc, SVal Val,
                                const LocationContext *LCtx);
  
    /// A simple wrapper when you only need to notify checkers of pointer-escape
    /// of some values.
    ProgramStateRef escapeValues(ProgramStateRef State, ArrayRef<SVal> Vs,
                                 PointerEscapeKind K,
                                 const CallEvent *Call = nullptr) const;
  
  public:
    // FIXME: 'tag' should be removed, and a LocationContext should be used
    // instead.
    // FIXME: Comment on the meaning of the arguments, when 'St' may not
    // be the same as Pred->state, and when 'location' may not be the
    // same as state->getLValue(Ex).
    /// Simulate a read of the result of Ex.
    void evalLoad(ExplodedNodeSet &Dst,
                  const Expr *NodeEx,  /* Eventually will be a CFGStmt */
                  const Expr *BoundExpr,
                  ExplodedNode *Pred,
                  ProgramStateRef St,
                  SVal location,
                  const ProgramPointTag *tag = nullptr,
                  QualType LoadTy = QualType());
  
    // FIXME: 'tag' should be removed, and a LocationContext should be used
    // instead.
    void evalStore(ExplodedNodeSet &Dst, const Expr *AssignE, const Expr *StoreE,
                   ExplodedNode *Pred, ProgramStateRef St, SVal TargetLV, SVal Val,
                   const ProgramPointTag *tag = nullptr);
  
    /// Return the CFG element corresponding to the worklist element
    /// that is currently being processed by ExprEngine.
    CFGElement getCurrentCFGElement() {
      return (*currBldrCtx->getBlock())[currStmtIdx];
    }
  
    /// Create a new state in which the call return value is binded to the
    /// call origin expression.
    ProgramStateRef bindReturnValue(const CallEvent &Call,
                                    const LocationContext *LCtx,
                                    ProgramStateRef State);
  
    /// Evaluate a call, running pre- and post-call checkers and allowing checkers
    /// to be responsible for handling the evaluation of the call itself.
    void evalCall(ExplodedNodeSet &Dst, ExplodedNode *Pred,
                  const CallEvent &Call);
  
    /// Default implementation of call evaluation.
    void defaultEvalCall(NodeBuilder &B, ExplodedNode *Pred,
                         const CallEvent &Call,
                         const EvalCallOptions &CallOpts = {});
  
    /// Find location of the object that is being constructed by a given
    /// constructor. This should ideally always succeed but due to not being
    /// fully implemented it sometimes indicates that it failed via its
    /// out-parameter CallOpts; in such cases a fake temporary region is
    /// returned, which is better than nothing but does not represent
    /// the actual behavior of the program.
    SVal computeObjectUnderConstruction(
        const Expr *E, ProgramStateRef State, const LocationContext *LCtx,
        const ConstructionContext *CC, EvalCallOptions &CallOpts);
  
    /// Update the program state with all the path-sensitive information
    /// that's necessary to perform construction of an object with a given
    /// syntactic construction context. V and CallOpts have to be obtained from
    /// computeObjectUnderConstruction() invoked with the same set of
    /// the remaining arguments (E, State, LCtx, CC).
    ProgramStateRef updateObjectsUnderConstruction(
        SVal V, const Expr *E, ProgramStateRef State, const LocationContext *LCtx,
        const ConstructionContext *CC, const EvalCallOptions &CallOpts);
  
    /// A convenient wrapper around computeObjectUnderConstruction
    /// and updateObjectsUnderConstruction.
    std::pair<ProgramStateRef, SVal> handleConstructionContext(
        const Expr *E, ProgramStateRef State, const LocationContext *LCtx,
        const ConstructionContext *CC, EvalCallOptions &CallOpts) {
      SVal V = computeObjectUnderConstruction(E, State, LCtx, CC, CallOpts);
      return std::make_pair(
          updateObjectsUnderConstruction(V, E, State, LCtx, CC, CallOpts), V);
    }
  
  private:
    ProgramStateRef finishArgumentConstruction(ProgramStateRef State,
                                               const CallEvent &Call);
    void finishArgumentConstruction(ExplodedNodeSet &Dst, ExplodedNode *Pred,
                                    const CallEvent &Call);
  
    void evalLoadCommon(ExplodedNodeSet &Dst,
                        const Expr *NodeEx,  /* Eventually will be a CFGStmt */
                        const Expr *BoundEx,
                        ExplodedNode *Pred,
                        ProgramStateRef St,
                        SVal location,
                        const ProgramPointTag *tag,
                        QualType LoadTy);
  
    void evalLocation(ExplodedNodeSet &Dst,
                      const Stmt *NodeEx, /* This will eventually be a CFGStmt */
                      const Stmt *BoundEx,
                      ExplodedNode *Pred,
                      ProgramStateRef St,
                      SVal location,
                      bool isLoad);
  
    /// Count the stack depth and determine if the call is recursive.
    void examineStackFrames(const Decl *D, const LocationContext *LCtx,
                            bool &IsRecursive, unsigned &StackDepth);
  
    enum CallInlinePolicy {
      CIP_Allowed,
      CIP_DisallowedOnce,
      CIP_DisallowedAlways
    };
  
    /// See if a particular call should be inlined, by only looking
    /// at the call event and the current state of analysis.
    CallInlinePolicy mayInlineCallKind(const CallEvent &Call,
                                       const ExplodedNode *Pred,
                                       AnalyzerOptions &Opts,
                                       const EvalCallOptions &CallOpts);
  
    /// See if the given AnalysisDeclContext is built for a function that we
    /// should always inline simply because it's small enough.
    /// Apart from "small" functions, we also have "large" functions
    /// (cf. isLarge()), some of which are huge (cf. isHuge()), and we classify
    /// the remaining functions as "medium".
    bool isSmall(AnalysisDeclContext *ADC) const;
  
    /// See if the given AnalysisDeclContext is built for a function that we
    /// should inline carefully because it looks pretty large.
    bool isLarge(AnalysisDeclContext *ADC) const;
  
    /// See if the given AnalysisDeclContext is built for a function that we
    /// should never inline because it's legit gigantic.
    bool isHuge(AnalysisDeclContext *ADC) const;
  
    /// See if the given AnalysisDeclContext is built for a function that we
    /// should inline, just by looking at the declaration of the function.
    bool mayInlineDecl(AnalysisDeclContext *ADC) const;
  
    /// Checks our policies and decides weither the given call should be inlined.
    bool shouldInlineCall(const CallEvent &Call, const Decl *D,
                          const ExplodedNode *Pred,
                          const EvalCallOptions &CallOpts = {});
  
    bool inlineCall(const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
                    ExplodedNode *Pred, ProgramStateRef State);
  
    /// Conservatively evaluate call by invalidating regions and binding
    /// a conjured return value.
    void conservativeEvalCall(const CallEvent &Call, NodeBuilder &Bldr,
                              ExplodedNode *Pred, ProgramStateRef State);
  
    /// Either inline or process the call conservatively (or both), based
    /// on DynamicDispatchBifurcation data.
    void BifurcateCall(const MemRegion *BifurReg,
                       const CallEvent &Call, const Decl *D, NodeBuilder &Bldr,
                       ExplodedNode *Pred);
  
    bool replayWithoutInlining(ExplodedNode *P, const LocationContext *CalleeLC);
  
    /// Models a trivial copy or move constructor or trivial assignment operator
    /// call with a simple bind.
    void performTrivialCopy(NodeBuilder &Bldr, ExplodedNode *Pred,
                            const CallEvent &Call);
  
    /// If the value of the given expression \p InitWithAdjustments is a NonLoc,
    /// copy it into a new temporary object region, and replace the value of the
    /// expression with that.
    ///
    /// If \p Result is provided, the new region will be bound to this expression
    /// instead of \p InitWithAdjustments.
    ///
    /// Returns the temporary region with adjustments into the optional
    /// OutRegionWithAdjustments out-parameter if a new region was indeed needed,
    /// otherwise sets it to nullptr.
    ProgramStateRef createTemporaryRegionIfNeeded(
        ProgramStateRef State, const LocationContext *LC,
        const Expr *InitWithAdjustments, const Expr *Result = nullptr,
        const SubRegion **OutRegionWithAdjustments = nullptr);
  
    /// Returns a region representing the first element of a (possibly
    /// multi-dimensional) array, for the purposes of element construction or
    /// destruction.
    ///
    /// On return, \p Ty will be set to the base type of the array.
    ///
    /// If the type is not an array type at all, the original value is returned.
    /// Otherwise the "IsArray" flag is set.
    static SVal makeZeroElementRegion(ProgramStateRef State, SVal LValue,
                                      QualType &Ty, bool &IsArray);
  
    /// For a DeclStmt or CXXInitCtorInitializer, walk backward in the current CFG
    /// block to find the constructor expression that directly constructed into
    /// the storage for this statement. Returns null if the constructor for this
    /// statement created a temporary object region rather than directly
    /// constructing into an existing region.
    const CXXConstructExpr *findDirectConstructorForCurrentCFGElement();
  
    /// Common code that handles either a CXXConstructExpr or a
    /// CXXInheritedCtorInitExpr.
    void handleConstructor(const Expr *E, ExplodedNode *Pred,
                           ExplodedNodeSet &Dst);
  
    /// Store the location of a C++ object corresponding to a statement
    /// until the statement is actually encountered. For example, if a DeclStmt
    /// has CXXConstructExpr as its initializer, the object would be considered
    /// to be "under construction" between CXXConstructExpr and DeclStmt.
    /// This allows, among other things, to keep bindings to variable's fields
    /// made within the constructor alive until its declaration actually
    /// goes into scope.
    static ProgramStateRef
    addObjectUnderConstruction(ProgramStateRef State,
                               const ConstructionContextItem &Item,
                               const LocationContext *LC, SVal V);
  
    /// Mark the object sa fully constructed, cleaning up the state trait
    /// that tracks objects under construction.
    static ProgramStateRef
    finishObjectConstruction(ProgramStateRef State,
                             const ConstructionContextItem &Item,
                             const LocationContext *LC);
  
    /// If the given expression corresponds to a temporary that was used for
    /// passing into an elidable copy/move constructor and that constructor
    /// was actually elided, track that we also need to elide the destructor.
    static ProgramStateRef elideDestructor(ProgramStateRef State,
                                           const CXXBindTemporaryExpr *BTE,
                                           const LocationContext *LC);
  
    /// Stop tracking the destructor that corresponds to an elided constructor.
    static ProgramStateRef
    cleanupElidedDestructor(ProgramStateRef State,
                            const CXXBindTemporaryExpr *BTE,
                            const LocationContext *LC);
  
    /// Returns true if the given expression corresponds to a temporary that
    /// was constructed for passing into an elidable copy/move constructor
    /// and that constructor was actually elided.
    static bool isDestructorElided(ProgramStateRef State,
                                   const CXXBindTemporaryExpr *BTE,
                                   const LocationContext *LC);
  
    /// Check if all objects under construction have been fully constructed
    /// for the given context range (including FromLC, not including ToLC).
    /// This is useful for assertions. Also checks if elided destructors
    /// were cleaned up.
    static bool areAllObjectsFullyConstructed(ProgramStateRef State,
                                              const LocationContext *FromLC,
                                              const LocationContext *ToLC);
  };
  
  /// Traits for storing the call processing policy inside GDM.
  /// The GDM stores the corresponding CallExpr pointer.
  // FIXME: This does not use the nice trait macros because it must be accessible
  // from multiple translation units.
  struct ReplayWithoutInlining{};
  template <>
  struct ProgramStateTrait<ReplayWithoutInlining> :
    public ProgramStatePartialTrait<const void*> {
    static void *GDMIndex();
  };
  
  } // namespace ento
  
  } // namespace clang
  
  #endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_EXPRENGINE_H
  