Coverage Report

Created: 2020-09-19 12:23

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/include/clang/StaticAnalyzer/Core/PathSensitive/Store.h
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//===- Store.h - Interface for maps from Locations to Values ----*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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//  This file defined the types Store and StoreManager.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_STORE_H
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#define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_STORE_H
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#include "clang/AST/Type.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/StoreRef.h"
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#include "clang/StaticAnalyzer/Core/PathSensitive/SymExpr.h"
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#include "clang/Basic/LLVM.h"
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#include "llvm/ADT/ArrayRef.h"
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#include "llvm/ADT/DenseSet.h"
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#include "llvm/ADT/Optional.h"
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#include "llvm/ADT/SmallVector.h"
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#include <cassert>
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#include <cstdint>
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#include <memory>
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namespace clang {
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class ASTContext;
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class CastExpr;
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class CompoundLiteralExpr;
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class CXXBasePath;
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class Decl;
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class Expr;
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class LocationContext;
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class ObjCIvarDecl;
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class StackFrameContext;
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namespace ento {
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class CallEvent;
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class ProgramStateManager;
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class ScanReachableSymbols;
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class SymbolReaper;
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using InvalidatedSymbols = llvm::DenseSet<SymbolRef>;
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class StoreManager {
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protected:
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  SValBuilder &svalBuilder;
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  ProgramStateManager &StateMgr;
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  /// MRMgr - Manages region objects associated with this StoreManager.
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  MemRegionManager &MRMgr;
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  ASTContext &Ctx;
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  StoreManager(ProgramStateManager &stateMgr);
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public:
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  virtual ~StoreManager() = default;
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  /// Return the value bound to specified location in a given state.
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  /// \param[in] store The store in which to make the lookup.
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  /// \param[in] loc The symbolic memory location.
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  /// \param[in] T An optional type that provides a hint indicating the
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  ///   expected type of the returned value.  This is used if the value is
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  ///   lazily computed.
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  /// \return The value bound to the location \c loc.
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  virtual SVal getBinding(Store store, Loc loc, QualType T = QualType()) = 0;
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  /// Return the default value bound to a region in a given store. The default
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  /// binding is the value of sub-regions that were not initialized separately
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  /// from their base region. For example, if the structure is zero-initialized
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  /// upon construction, this method retrieves the concrete zero value, even if
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  /// some or all fields were later overwritten manually. Default binding may be
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  /// an unknown, undefined, concrete, or symbolic value.
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  /// \param[in] store The store in which to make the lookup.
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  /// \param[in] R The region to find the default binding for.
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  /// \return The default value bound to the region in the store, if a default
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  /// binding exists.
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  virtual Optional<SVal> getDefaultBinding(Store store, const MemRegion *R) = 0;
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  /// Return the default value bound to a LazyCompoundVal. The default binding
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  /// is used to represent the value of any fields or elements within the
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  /// structure represented by the LazyCompoundVal which were not initialized
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  /// explicitly separately from the whole structure. Default binding may be an
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  /// unknown, undefined, concrete, or symbolic value.
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  /// \param[in] lcv The lazy compound value.
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  /// \return The default value bound to the LazyCompoundVal \c lcv, if a
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  /// default binding exists.
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  Optional<SVal> getDefaultBinding(nonloc::LazyCompoundVal lcv) {
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    return getDefaultBinding(lcv.getStore(), lcv.getRegion());
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  }
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  /// Return a store with the specified value bound to the given location.
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  /// \param[in] store The store in which to make the binding.
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  /// \param[in] loc The symbolic memory location.
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  /// \param[in] val The value to bind to location \c loc.
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  /// \return A StoreRef object that contains the same
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  ///   bindings as \c store with the addition of having the value specified
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  ///   by \c val bound to the location given for \c loc.
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  virtual StoreRef Bind(Store store, Loc loc, SVal val) = 0;
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  /// Return a store with the specified value bound to all sub-regions of the
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  /// region. The region must not have previous bindings. If you need to
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  /// invalidate existing bindings, consider invalidateRegions().
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  virtual StoreRef BindDefaultInitial(Store store, const MemRegion *R,
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                                      SVal V) = 0;
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  /// Return a store with in which all values within the given region are
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  /// reset to zero. This method is allowed to overwrite previous bindings.
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  virtual StoreRef BindDefaultZero(Store store, const MemRegion *R) = 0;
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  /// Create a new store with the specified binding removed.
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  /// \param ST the original store, that is the basis for the new store.
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  /// \param L the location whose binding should be removed.
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  virtual StoreRef killBinding(Store ST, Loc L) = 0;
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  /// getInitialStore - Returns the initial "empty" store representing the
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  ///  value bindings upon entry to an analyzed function.
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  virtual StoreRef getInitialStore(const LocationContext *InitLoc) = 0;
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  /// getRegionManager - Returns the internal RegionManager object that is
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  ///  used to query and manipulate MemRegion objects.
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  MemRegionManager& getRegionManager() { return MRMgr; }
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  SValBuilder& getSValBuilder() { return svalBuilder; }
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  virtual Loc getLValueVar(const VarDecl *VD, const LocationContext *LC) {
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    return svalBuilder.makeLoc(MRMgr.getVarRegion(VD, LC));
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  }
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  Loc getLValueCompoundLiteral(const CompoundLiteralExpr *CL,
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                               const LocationContext *LC) {
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    return loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL, LC));
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  }
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  virtual SVal getLValueIvar(const ObjCIvarDecl *decl, SVal base);
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  virtual SVal getLValueField(const FieldDecl *D, SVal Base) {
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    return getLValueFieldOrIvar(D, Base);
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  }
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  virtual SVal getLValueElement(QualType elementType, NonLoc offset, SVal Base);
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  /// ArrayToPointer - Used by ExprEngine::VistCast to handle implicit
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  ///  conversions between arrays and pointers.
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  virtual SVal ArrayToPointer(Loc Array, QualType ElementTy) = 0;
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  /// Evaluates a chain of derived-to-base casts through the path specified in
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  /// \p Cast.
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  SVal evalDerivedToBase(SVal Derived, const CastExpr *Cast);
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  /// Evaluates a chain of derived-to-base casts through the specified path.
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  SVal evalDerivedToBase(SVal Derived, const CXXBasePath &CastPath);
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  /// Evaluates a derived-to-base cast through a single level of derivation.
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  SVal evalDerivedToBase(SVal Derived, QualType DerivedPtrType,
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                         bool IsVirtual);
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  /// Attempts to do a down cast. Used to model BaseToDerived and C++
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  ///        dynamic_cast.
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  /// The callback may result in the following 3 scenarios:
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  ///  - Successful cast (ex: derived is subclass of base).
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  ///  - Failed cast (ex: derived is definitely not a subclass of base).
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  ///    The distinction of this case from the next one is necessary to model
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  ///    dynamic_cast.
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  ///  - We don't know (base is a symbolic region and we don't have
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  ///    enough info to determine if the cast will succeed at run time).
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  /// The function returns an SVal representing the derived class; it's
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  /// valid only if Failed flag is set to false.
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  SVal attemptDownCast(SVal Base, QualType DerivedPtrType, bool &Failed);
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  const ElementRegion *GetElementZeroRegion(const SubRegion *R, QualType T);
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  /// castRegion - Used by ExprEngine::VisitCast to handle casts from
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  ///  a MemRegion* to a specific location type.  'R' is the region being
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  ///  casted and 'CastToTy' the result type of the cast.
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  const MemRegion *castRegion(const MemRegion *region, QualType CastToTy);
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  virtual StoreRef removeDeadBindings(Store store, const StackFrameContext *LCtx,
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                                      SymbolReaper &SymReaper) = 0;
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  virtual bool includedInBindings(Store store,
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                                  const MemRegion *region) const = 0;
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  /// If the StoreManager supports it, increment the reference count of
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  /// the specified Store object.
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  virtual void incrementReferenceCount(Store store) {}
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  /// If the StoreManager supports it, decrement the reference count of
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  /// the specified Store object.  If the reference count hits 0, the memory
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  /// associated with the object is recycled.
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  virtual void decrementReferenceCount(Store store) {}
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  using InvalidatedRegions = SmallVector<const MemRegion *, 8>;
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  /// invalidateRegions - Clears out the specified regions from the store,
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  ///  marking their values as unknown. Depending on the store, this may also
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  ///  invalidate additional regions that may have changed based on accessing
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  ///  the given regions. Optionally, invalidates non-static globals as well.
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  /// \param[in] store The initial store
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  /// \param[in] Values The values to invalidate.
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  /// \param[in] E The current statement being evaluated. Used to conjure
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  ///   symbols to mark the values of invalidated regions.
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  /// \param[in] Count The current block count. Used to conjure
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  ///   symbols to mark the values of invalidated regions.
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  /// \param[in] Call The call expression which will be used to determine which
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  ///   globals should get invalidated.
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  /// \param[in,out] IS A set to fill with any symbols that are no longer
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  ///   accessible. Pass \c NULL if this information will not be used.
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  /// \param[in] ITraits Information about invalidation for a particular
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  ///   region/symbol.
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  /// \param[in,out] InvalidatedTopLevel A vector to fill with regions
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  ////  explicitly being invalidated. Pass \c NULL if this
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  ///   information will not be used.
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  /// \param[in,out] Invalidated A vector to fill with any regions being
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  ///   invalidated. This should include any regions explicitly invalidated
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  ///   even if they do not currently have bindings. Pass \c NULL if this
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  ///   information will not be used.
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  virtual StoreRef invalidateRegions(Store store,
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                                  ArrayRef<SVal> Values,
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                                  const Expr *E, unsigned Count,
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                                  const LocationContext *LCtx,
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                                  const CallEvent *Call,
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                                  InvalidatedSymbols &IS,
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                                  RegionAndSymbolInvalidationTraits &ITraits,
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                                  InvalidatedRegions *InvalidatedTopLevel,
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                                  InvalidatedRegions *Invalidated) = 0;
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  /// enterStackFrame - Let the StoreManager to do something when execution
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  /// engine is about to execute into a callee.
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  StoreRef enterStackFrame(Store store,
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                           const CallEvent &Call,
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                           const StackFrameContext *CalleeCtx);
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  /// Finds the transitive closure of symbols within the given region.
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  ///
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  /// Returns false if the visitor aborted the scan.
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  virtual bool scanReachableSymbols(Store S, const MemRegion *R,
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                                    ScanReachableSymbols &Visitor) = 0;
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  virtual void printJson(raw_ostream &Out, Store S, const char *NL,
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                         unsigned int Space, bool IsDot) const = 0;
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  class BindingsHandler {
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  public:
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    virtual ~BindingsHandler();
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    /// \return whether the iteration should continue.
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    virtual bool HandleBinding(StoreManager& SMgr, Store store,
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                               const MemRegion *region, SVal val) = 0;
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  };
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  class FindUniqueBinding : public BindingsHandler {
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    SymbolRef Sym;
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    const MemRegion* Binding = nullptr;
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    bool First = true;
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  public:
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    FindUniqueBinding(SymbolRef sym) : Sym(sym) {}
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    explicit operator bool() { return First && 
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; }
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    bool HandleBinding(StoreManager& SMgr, Store store, const MemRegion* R,
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                       SVal val) override;
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    const MemRegion *getRegion() { return Binding; }
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  };
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  /// iterBindings - Iterate over the bindings in the Store.
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  virtual void iterBindings(Store store, BindingsHandler& f) = 0;
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protected:
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  const ElementRegion *MakeElementRegion(const SubRegion *baseRegion,
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                                         QualType pointeeTy,
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                                         uint64_t index = 0);
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  /// CastRetrievedVal - Used by subclasses of StoreManager to implement
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  ///  implicit casts that arise from loads from regions that are reinterpreted
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  ///  as another region.
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  SVal CastRetrievedVal(SVal val, const TypedValueRegion *region,
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                        QualType castTy);
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private:
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  SVal getLValueFieldOrIvar(const Decl *decl, SVal base);
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};
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inline StoreRef::StoreRef(Store store, StoreManager & smgr)
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    : store(store), mgr(smgr) {
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  if (store)
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    mgr.incrementReferenceCount(store);
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}
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inline StoreRef::StoreRef(const StoreRef &sr)
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    : store(sr.store), mgr(sr.mgr)
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{
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  if (store)
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    mgr.incrementReferenceCount(store);
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}
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inline StoreRef::~StoreRef() {
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  if (store)
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    mgr.decrementReferenceCount(store);
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}
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inline StoreRef &StoreRef::operator=(StoreRef const &newStore) {
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  assert(&newStore.mgr == &mgr);
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  if (store != newStore.store) {
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    mgr.incrementReferenceCount(newStore.store);
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    mgr.decrementReferenceCount(store);
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    store = newStore.getStore();
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  }
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  return *this;
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}
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// FIXME: Do we need to pass ProgramStateManager anymore?
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std::unique_ptr<StoreManager>
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CreateRegionStoreManager(ProgramStateManager &StMgr);
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std::unique_ptr<StoreManager>
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CreateFieldsOnlyRegionStoreManager(ProgramStateManager &StMgr);
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} // namespace ento
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} // namespace clang
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#endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_STORE_H