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