| //== RegionStore.cpp - Field-sensitive store model --------------*- C++ -*--==// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file defines a basic region store model. In this model, we do have field |
| // sensitivity. But we assume nothing about the heap shape. So recursive data |
| // structures are largely ignored. Basically we do 1-limiting analysis. |
| // Parameter pointers are assumed with no aliasing. Pointee objects of |
| // parameters are created lazily. |
| // |
| //===----------------------------------------------------------------------===// |
| #include "clang/Analysis/PathSensitive/MemRegion.h" |
| #include "clang/Analysis/PathSensitive/GRState.h" |
| #include "clang/Analysis/PathSensitive/GRStateTrait.h" |
| #include "clang/Analysis/Analyses/LiveVariables.h" |
| #include "clang/Basic/TargetInfo.h" |
| |
| #include "llvm/ADT/ImmutableMap.h" |
| #include "llvm/ADT/ImmutableList.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/Support/Compiler.h" |
| |
| using namespace clang; |
| |
| // Actual Store type. |
| typedef llvm::ImmutableMap<const MemRegion*, SVal> RegionBindingsTy; |
| |
| //===----------------------------------------------------------------------===// |
| // Fine-grained control of RegionStoreManager. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| struct VISIBILITY_HIDDEN minimal_features_tag {}; |
| struct VISIBILITY_HIDDEN maximal_features_tag {}; |
| |
| class VISIBILITY_HIDDEN RegionStoreFeatures { |
| bool SupportsFields; |
| bool SupportsRemaining; |
| |
| public: |
| RegionStoreFeatures(minimal_features_tag) : |
| SupportsFields(false), SupportsRemaining(false) {} |
| |
| RegionStoreFeatures(maximal_features_tag) : |
| SupportsFields(true), SupportsRemaining(false) {} |
| |
| void enableFields(bool t) { SupportsFields = t; } |
| |
| bool supportsFields() const { return SupportsFields; } |
| bool supportsRemaining() const { return SupportsRemaining; } |
| }; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Region "Views" |
| //===----------------------------------------------------------------------===// |
| // |
| // MemRegions can be layered on top of each other. This GDM entry tracks |
| // what are the MemRegions that layer a given MemRegion. |
| // |
| typedef llvm::ImmutableSet<const MemRegion*> RegionViews; |
| namespace { class VISIBILITY_HIDDEN RegionViewMap {}; } |
| static int RegionViewMapIndex = 0; |
| namespace clang { |
| template<> struct GRStateTrait<RegionViewMap> |
| : public GRStatePartialTrait<llvm::ImmutableMap<const MemRegion*, |
| RegionViews> > { |
| |
| static void* GDMIndex() { return &RegionViewMapIndex; } |
| }; |
| } |
| |
| // RegionCasts records the current cast type of a region. |
| namespace { class VISIBILITY_HIDDEN RegionCasts {}; } |
| static int RegionCastsIndex = 0; |
| namespace clang { |
| template<> struct GRStateTrait<RegionCasts> |
| : public GRStatePartialTrait<llvm::ImmutableMap<const MemRegion*, |
| QualType> > { |
| static void* GDMIndex() { return &RegionCastsIndex; } |
| }; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Region "Extents" |
| //===----------------------------------------------------------------------===// |
| // |
| // MemRegions represent chunks of memory with a size (their "extent"). This |
| // GDM entry tracks the extents for regions. Extents are in bytes. |
| // |
| namespace { class VISIBILITY_HIDDEN RegionExtents {}; } |
| static int RegionExtentsIndex = 0; |
| namespace clang { |
| template<> struct GRStateTrait<RegionExtents> |
| : public GRStatePartialTrait<llvm::ImmutableMap<const MemRegion*, SVal> > { |
| static void* GDMIndex() { return &RegionExtentsIndex; } |
| }; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Regions with default values. |
| //===----------------------------------------------------------------------===// |
| // |
| // This GDM entry tracks what regions have a default value if they have no bound |
| // value and have not been killed. |
| // |
| namespace { class VISIBILITY_HIDDEN RegionDefaultValue {}; } |
| static int RegionDefaultValueIndex = 0; |
| namespace clang { |
| template<> struct GRStateTrait<RegionDefaultValue> |
| : public GRStatePartialTrait<llvm::ImmutableMap<const MemRegion*, SVal> > { |
| static void* GDMIndex() { return &RegionDefaultValueIndex; } |
| }; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Main RegionStore logic. |
| //===----------------------------------------------------------------------===// |
| |
| namespace { |
| |
| class VISIBILITY_HIDDEN RegionStoreSubRegionMap : public SubRegionMap { |
| typedef llvm::DenseMap<const MemRegion*, |
| llvm::ImmutableSet<const MemRegion*> > Map; |
| |
| llvm::ImmutableSet<const MemRegion*>::Factory F; |
| Map M; |
| |
| public: |
| void add(const MemRegion* Parent, const MemRegion* SubRegion) { |
| Map::iterator I = M.find(Parent); |
| M.insert(std::make_pair(Parent, |
| F.Add(I == M.end() ? F.GetEmptySet() : I->second, SubRegion))); |
| } |
| |
| ~RegionStoreSubRegionMap() {} |
| |
| bool iterSubRegions(const MemRegion* Parent, Visitor& V) const { |
| Map::iterator I = M.find(Parent); |
| |
| if (I == M.end()) |
| return true; |
| |
| llvm::ImmutableSet<const MemRegion*> S = I->second; |
| for (llvm::ImmutableSet<const MemRegion*>::iterator SI=S.begin(),SE=S.end(); |
| SI != SE; ++SI) { |
| if (!V.Visit(Parent, *SI)) |
| return false; |
| } |
| |
| return true; |
| } |
| }; |
| |
| class VISIBILITY_HIDDEN RegionStoreManager : public StoreManager { |
| const RegionStoreFeatures Features; |
| RegionBindingsTy::Factory RBFactory; |
| RegionViews::Factory RVFactory; |
| |
| const MemRegion* SelfRegion; |
| const ImplicitParamDecl *SelfDecl; |
| |
| public: |
| RegionStoreManager(GRStateManager& mgr, const RegionStoreFeatures &f) |
| : StoreManager(mgr, true), |
| Features(f), |
| RBFactory(mgr.getAllocator()), |
| RVFactory(mgr.getAllocator()), |
| SelfRegion(0), SelfDecl(0) { |
| if (const ObjCMethodDecl* MD = |
| dyn_cast<ObjCMethodDecl>(&StateMgr.getCodeDecl())) |
| SelfDecl = MD->getSelfDecl(); |
| } |
| |
| virtual ~RegionStoreManager() {} |
| |
| SubRegionMap* getSubRegionMap(const GRState *state); |
| |
| /// getLValueString - Returns an SVal representing the lvalue of a |
| /// StringLiteral. Within RegionStore a StringLiteral has an |
| /// associated StringRegion, and the lvalue of a StringLiteral is |
| /// the lvalue of that region. |
| SVal getLValueString(const GRState *state, const StringLiteral* S); |
| |
| /// getLValueCompoundLiteral - Returns an SVal representing the |
| /// lvalue of a compound literal. Within RegionStore a compound |
| /// literal has an associated region, and the lvalue of the |
| /// compound literal is the lvalue of that region. |
| SVal getLValueCompoundLiteral(const GRState *state, const CompoundLiteralExpr*); |
| |
| /// getLValueVar - Returns an SVal that represents the lvalue of a |
| /// variable. Within RegionStore a variable has an associated |
| /// VarRegion, and the lvalue of the variable is the lvalue of that region. |
| SVal getLValueVar(const GRState *state, const VarDecl* VD); |
| |
| SVal getLValueIvar(const GRState *state, const ObjCIvarDecl* D, SVal Base); |
| |
| SVal getLValueField(const GRState *state, SVal Base, const FieldDecl* D); |
| |
| SVal getLValueFieldOrIvar(const GRState *state, SVal Base, const Decl* D); |
| |
| SVal getLValueElement(const GRState *state, QualType elementType, |
| SVal Base, SVal Offset); |
| |
| |
| /// ArrayToPointer - Emulates the "decay" of an array to a pointer |
| /// type. 'Array' represents the lvalue of the array being decayed |
| /// to a pointer, and the returned SVal represents the decayed |
| /// version of that lvalue (i.e., a pointer to the first element of |
| /// the array). This is called by GRExprEngine when evaluating |
| /// casts from arrays to pointers. |
| SVal ArrayToPointer(Loc Array); |
| |
| SVal EvalBinOp(const GRState *state, BinaryOperator::Opcode Op,Loc L, |
| NonLoc R, QualType resultTy); |
| |
| Store getInitialStore() { return RBFactory.GetEmptyMap().getRoot(); } |
| |
| /// getSelfRegion - Returns the region for the 'self' (Objective-C) or |
| /// 'this' object (C++). When used when analyzing a normal function this |
| /// method returns NULL. |
| const MemRegion* getSelfRegion(Store) { |
| if (!SelfDecl) |
| return 0; |
| |
| if (!SelfRegion) { |
| const ObjCMethodDecl *MD = cast<ObjCMethodDecl>(&StateMgr.getCodeDecl()); |
| SelfRegion = MRMgr.getObjCObjectRegion(MD->getClassInterface(), |
| MRMgr.getHeapRegion()); |
| } |
| |
| return SelfRegion; |
| } |
| |
| //===-------------------------------------------------------------------===// |
| // Binding values to regions. |
| //===-------------------------------------------------------------------===// |
| |
| const GRState *Bind(const GRState *state, Loc LV, SVal V); |
| |
| const GRState *BindCompoundLiteral(const GRState *state, |
| const CompoundLiteralExpr* CL, SVal V); |
| |
| const GRState *BindDecl(const GRState *state, const VarDecl* VD, SVal InitVal); |
| |
| const GRState *BindDeclWithNoInit(const GRState *state, const VarDecl* VD) { |
| return state; |
| } |
| |
| /// BindStruct - Bind a compound value to a structure. |
| const GRState *BindStruct(const GRState *, const TypedRegion* R, SVal V); |
| |
| const GRState *BindArray(const GRState *state, const TypedRegion* R, SVal V); |
| |
| /// KillStruct - Set the entire struct to unknown. |
| const GRState *KillStruct(const GRState *state, const TypedRegion* R); |
| |
| const GRState *setDefaultValue(const GRState *state, const MemRegion* R, SVal V); |
| |
| Store Remove(Store store, Loc LV); |
| |
| //===------------------------------------------------------------------===// |
| // Loading values from regions. |
| //===------------------------------------------------------------------===// |
| |
| /// The high level logic for this method is this: |
| /// Retrieve (L) |
| /// if L has binding |
| /// return L's binding |
| /// else if L is in killset |
| /// return unknown |
| /// else |
| /// if L is on stack or heap |
| /// return undefined |
| /// else |
| /// return symbolic |
| SVal Retrieve(const GRState *state, Loc L, QualType T = QualType()); |
| |
| SVal RetrieveElement(const GRState* state, const ElementRegion* R); |
| |
| SVal RetrieveField(const GRState* state, const FieldRegion* R); |
| |
| /// Retrieve the values in a struct and return a CompoundVal, used when doing |
| /// struct copy: |
| /// struct s x, y; |
| /// x = y; |
| /// y's value is retrieved by this method. |
| SVal RetrieveStruct(const GRState *St, const TypedRegion* R); |
| |
| SVal RetrieveArray(const GRState *St, const TypedRegion* R); |
| |
| //===------------------------------------------------------------------===// |
| // State pruning. |
| //===------------------------------------------------------------------===// |
| |
| /// RemoveDeadBindings - Scans the RegionStore of 'state' for dead values. |
| /// It returns a new Store with these values removed. |
| Store RemoveDeadBindings(const GRState *state, Stmt* Loc, SymbolReaper& SymReaper, |
| llvm::SmallVectorImpl<const MemRegion*>& RegionRoots); |
| |
| //===------------------------------------------------------------------===// |
| // Region "extents". |
| //===------------------------------------------------------------------===// |
| |
| const GRState *setExtent(const GRState *state, const MemRegion* R, SVal Extent); |
| SVal getSizeInElements(const GRState *state, const MemRegion* R); |
| |
| //===------------------------------------------------------------------===// |
| // Region "views". |
| //===------------------------------------------------------------------===// |
| |
| const GRState *AddRegionView(const GRState *state, const MemRegion* View, |
| const MemRegion* Base); |
| |
| const GRState *RemoveRegionView(const GRState *state, const MemRegion* View, |
| const MemRegion* Base); |
| |
| //===------------------------------------------------------------------===// |
| // Utility methods. |
| //===------------------------------------------------------------------===// |
| |
| const GRState *setCastType(const GRState *state, const MemRegion* R, |
| QualType T); |
| |
| const QualType *getCastType(const GRState *state, const MemRegion *R) { |
| return state->get<RegionCasts>(R); |
| } |
| |
| static inline RegionBindingsTy GetRegionBindings(Store store) { |
| return RegionBindingsTy(static_cast<const RegionBindingsTy::TreeTy*>(store)); |
| } |
| |
| void print(Store store, llvm::raw_ostream& Out, const char* nl, |
| const char *sep); |
| |
| void iterBindings(Store store, BindingsHandler& f) { |
| // FIXME: Implement. |
| } |
| |
| // FIXME: Remove. |
| BasicValueFactory& getBasicVals() { |
| return StateMgr.getBasicVals(); |
| } |
| |
| // FIXME: Remove. |
| ASTContext& getContext() { return StateMgr.getContext(); } |
| }; |
| |
| } // end anonymous namespace |
| |
| static bool isGenericPtr(ASTContext &Ctx, QualType Ty) { |
| if (Ty->isObjCIdType() || Ty->isObjCQualifiedIdType()) |
| return true; |
| |
| while (true) { |
| Ty = Ctx.getCanonicalType(Ty); |
| |
| if (Ty->isVoidType()) |
| return true; |
| |
| if (const PointerType *PT = Ty->getAsPointerType()) { |
| Ty = PT->getPointeeType(); |
| continue; |
| } |
| |
| break; |
| } |
| |
| return false; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // RegionStore creation. |
| //===----------------------------------------------------------------------===// |
| |
| StoreManager *clang::CreateRegionStoreManager(GRStateManager& StMgr) { |
| RegionStoreFeatures F = maximal_features_tag(); |
| return new RegionStoreManager(StMgr, F); |
| } |
| |
| StoreManager *clang::CreateFieldsOnlyRegionStoreManager(GRStateManager &StMgr) { |
| RegionStoreFeatures F = minimal_features_tag(); |
| F.enableFields(true); |
| return new RegionStoreManager(StMgr, F); |
| } |
| |
| SubRegionMap* RegionStoreManager::getSubRegionMap(const GRState *state) { |
| RegionBindingsTy B = GetRegionBindings(state->getStore()); |
| RegionStoreSubRegionMap *M = new RegionStoreSubRegionMap(); |
| |
| for (RegionBindingsTy::iterator I=B.begin(), E=B.end(); I!=E; ++I) { |
| if (const SubRegion* R = dyn_cast<SubRegion>(I.getKey())) |
| M->add(R->getSuperRegion(), R); |
| } |
| |
| return M; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // getLValueXXX methods. |
| //===----------------------------------------------------------------------===// |
| |
| /// getLValueString - Returns an SVal representing the lvalue of a |
| /// StringLiteral. Within RegionStore a StringLiteral has an |
| /// associated StringRegion, and the lvalue of a StringLiteral is the |
| /// lvalue of that region. |
| SVal RegionStoreManager::getLValueString(const GRState *St, |
| const StringLiteral* S) { |
| return loc::MemRegionVal(MRMgr.getStringRegion(S)); |
| } |
| |
| /// getLValueVar - Returns an SVal that represents the lvalue of a |
| /// variable. Within RegionStore a variable has an associated |
| /// VarRegion, and the lvalue of the variable is the lvalue of that region. |
| SVal RegionStoreManager::getLValueVar(const GRState *St, const VarDecl* VD) { |
| return loc::MemRegionVal(MRMgr.getVarRegion(VD)); |
| } |
| |
| /// getLValueCompoundLiteral - Returns an SVal representing the lvalue |
| /// of a compound literal. Within RegionStore a compound literal |
| /// has an associated region, and the lvalue of the compound literal |
| /// is the lvalue of that region. |
| SVal |
| RegionStoreManager::getLValueCompoundLiteral(const GRState *St, |
| const CompoundLiteralExpr* CL) { |
| return loc::MemRegionVal(MRMgr.getCompoundLiteralRegion(CL)); |
| } |
| |
| SVal RegionStoreManager::getLValueIvar(const GRState *St, const ObjCIvarDecl* D, |
| SVal Base) { |
| return getLValueFieldOrIvar(St, Base, D); |
| } |
| |
| SVal RegionStoreManager::getLValueField(const GRState *St, SVal Base, |
| const FieldDecl* D) { |
| return getLValueFieldOrIvar(St, Base, D); |
| } |
| |
| SVal RegionStoreManager::getLValueFieldOrIvar(const GRState *St, SVal Base, |
| const Decl* D) { |
| if (Base.isUnknownOrUndef()) |
| return Base; |
| |
| Loc BaseL = cast<Loc>(Base); |
| const MemRegion* BaseR = 0; |
| |
| switch (BaseL.getSubKind()) { |
| case loc::MemRegionKind: |
| BaseR = cast<loc::MemRegionVal>(BaseL).getRegion(); |
| break; |
| |
| case loc::GotoLabelKind: |
| // These are anormal cases. Flag an undefined value. |
| return UndefinedVal(); |
| |
| case loc::ConcreteIntKind: |
| // While these seem funny, this can happen through casts. |
| // FIXME: What we should return is the field offset. For example, |
| // add the field offset to the integer value. That way funny things |
| // like this work properly: &(((struct foo *) 0xa)->f) |
| return Base; |
| |
| default: |
| assert(0 && "Unhandled Base."); |
| return Base; |
| } |
| |
| // NOTE: We must have this check first because ObjCIvarDecl is a subclass |
| // of FieldDecl. |
| if (const ObjCIvarDecl *ID = dyn_cast<ObjCIvarDecl>(D)) |
| return loc::MemRegionVal(MRMgr.getObjCIvarRegion(ID, BaseR)); |
| |
| return loc::MemRegionVal(MRMgr.getFieldRegion(cast<FieldDecl>(D), BaseR)); |
| } |
| |
| SVal RegionStoreManager::getLValueElement(const GRState *St, |
| QualType elementType, |
| SVal Base, SVal Offset) { |
| |
| // If the base is an unknown or undefined value, just return it back. |
| // FIXME: For absolute pointer addresses, we just return that value back as |
| // well, although in reality we should return the offset added to that |
| // value. |
| if (Base.isUnknownOrUndef() || isa<loc::ConcreteInt>(Base)) |
| return Base; |
| |
| // Only handle integer offsets... for now. |
| if (!isa<nonloc::ConcreteInt>(Offset)) |
| return UnknownVal(); |
| |
| const MemRegion* BaseRegion = cast<loc::MemRegionVal>(Base).getRegion(); |
| |
| // Pointer of any type can be cast and used as array base. |
| const ElementRegion *ElemR = dyn_cast<ElementRegion>(BaseRegion); |
| |
| if (!ElemR) { |
| // |
| // If the base region is not an ElementRegion, create one. |
| // This can happen in the following example: |
| // |
| // char *p = __builtin_alloc(10); |
| // p[1] = 8; |
| // |
| // Observe that 'p' binds to an AllocaRegion. |
| // |
| |
| // Offset might be unsigned. We have to convert it to signed ConcreteInt. |
| if (nonloc::ConcreteInt* CI = dyn_cast<nonloc::ConcreteInt>(&Offset)) { |
| const llvm::APSInt& OffI = CI->getValue(); |
| if (OffI.isUnsigned()) { |
| llvm::APSInt Tmp = OffI; |
| Tmp.setIsSigned(true); |
| Offset = ValMgr.makeIntVal(Tmp); |
| } |
| } |
| return loc::MemRegionVal(MRMgr.getElementRegion(elementType, Offset, |
| BaseRegion, getContext())); |
| } |
| |
| SVal BaseIdx = ElemR->getIndex(); |
| |
| if (!isa<nonloc::ConcreteInt>(BaseIdx)) |
| return UnknownVal(); |
| |
| const llvm::APSInt& BaseIdxI = cast<nonloc::ConcreteInt>(BaseIdx).getValue(); |
| const llvm::APSInt& OffI = cast<nonloc::ConcreteInt>(Offset).getValue(); |
| assert(BaseIdxI.isSigned()); |
| |
| // FIXME: This appears to be the assumption of this code. We should review |
| // whether or not BaseIdxI.getBitWidth() < OffI.getBitWidth(). If it |
| // can't we need to put a comment here. If it can, we should handle it. |
| assert(BaseIdxI.getBitWidth() >= OffI.getBitWidth()); |
| |
| const MemRegion *ArrayR = ElemR->getSuperRegion(); |
| SVal NewIdx; |
| |
| if (OffI.isUnsigned() || OffI.getBitWidth() < BaseIdxI.getBitWidth()) { |
| // 'Offset' might be unsigned. We have to convert it to signed and |
| // possibly extend it. |
| llvm::APSInt Tmp = OffI; |
| |
| if (OffI.getBitWidth() < BaseIdxI.getBitWidth()) |
| Tmp.extend(BaseIdxI.getBitWidth()); |
| |
| Tmp.setIsSigned(true); |
| Tmp += BaseIdxI; // Compute the new offset. |
| NewIdx = ValMgr.makeIntVal(Tmp); |
| } |
| else |
| NewIdx = nonloc::ConcreteInt(getBasicVals().getValue(BaseIdxI + OffI)); |
| |
| return loc::MemRegionVal(MRMgr.getElementRegion(elementType, NewIdx, ArrayR, |
| getContext())); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Extents for regions. |
| //===----------------------------------------------------------------------===// |
| |
| SVal RegionStoreManager::getSizeInElements(const GRState *state, |
| const MemRegion *R) { |
| |
| switch (R->getKind()) { |
| case MemRegion::MemSpaceRegionKind: |
| assert(0 && "Cannot index into a MemSpace"); |
| return UnknownVal(); |
| |
| case MemRegion::CodeTextRegionKind: |
| // Technically this can happen if people do funny things with casts. |
| return UnknownVal(); |
| |
| // Not yet handled. |
| case MemRegion::AllocaRegionKind: |
| case MemRegion::CompoundLiteralRegionKind: |
| case MemRegion::ElementRegionKind: |
| case MemRegion::FieldRegionKind: |
| case MemRegion::ObjCIvarRegionKind: |
| case MemRegion::ObjCObjectRegionKind: |
| case MemRegion::SymbolicRegionKind: |
| return UnknownVal(); |
| |
| case MemRegion::StringRegionKind: { |
| const StringLiteral* Str = cast<StringRegion>(R)->getStringLiteral(); |
| // We intentionally made the size value signed because it participates in |
| // operations with signed indices. |
| return ValMgr.makeIntVal(Str->getByteLength()+1, false); |
| } |
| |
| // TypedViewRegion will soon be removed. |
| case MemRegion::TypedViewRegionKind: |
| return UnknownVal(); |
| |
| case MemRegion::VarRegionKind: { |
| const VarRegion* VR = cast<VarRegion>(R); |
| // Get the type of the variable. |
| QualType T = VR->getDesugaredValueType(getContext()); |
| |
| // FIXME: Handle variable-length arrays. |
| if (isa<VariableArrayType>(T)) |
| return UnknownVal(); |
| |
| if (const ConstantArrayType* CAT = dyn_cast<ConstantArrayType>(T)) { |
| // return the size as signed integer. |
| return ValMgr.makeIntVal(CAT->getSize(), false); |
| } |
| |
| const QualType* CastTy = state->get<RegionCasts>(VR); |
| |
| // If the VarRegion is cast to other type, compute the size with respect to |
| // that type. |
| if (CastTy) { |
| QualType EleTy =cast<PointerType>(CastTy->getTypePtr())->getPointeeType(); |
| QualType VarTy = VR->getValueType(getContext()); |
| uint64_t EleSize = getContext().getTypeSize(EleTy); |
| uint64_t VarSize = getContext().getTypeSize(VarTy); |
| assert(VarSize != 0); |
| return ValMgr.makeIntVal(VarSize/EleSize, false); |
| } |
| |
| // Clients can use ordinary variables as if they were arrays. These |
| // essentially are arrays of size 1. |
| return ValMgr.makeIntVal(1, false); |
| } |
| |
| case MemRegion::BEG_DECL_REGIONS: |
| case MemRegion::END_DECL_REGIONS: |
| case MemRegion::BEG_TYPED_REGIONS: |
| case MemRegion::END_TYPED_REGIONS: |
| assert(0 && "Infeasible region"); |
| return UnknownVal(); |
| } |
| |
| assert(0 && "Unreachable"); |
| return UnknownVal(); |
| } |
| |
| const GRState *RegionStoreManager::setExtent(const GRState *state, |
| const MemRegion *region, |
| SVal extent) { |
| return state->set<RegionExtents>(region, extent); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Location and region casting. |
| //===----------------------------------------------------------------------===// |
| |
| /// ArrayToPointer - Emulates the "decay" of an array to a pointer |
| /// type. 'Array' represents the lvalue of the array being decayed |
| /// to a pointer, and the returned SVal represents the decayed |
| /// version of that lvalue (i.e., a pointer to the first element of |
| /// the array). This is called by GRExprEngine when evaluating casts |
| /// from arrays to pointers. |
| SVal RegionStoreManager::ArrayToPointer(Loc Array) { |
| if (!isa<loc::MemRegionVal>(Array)) |
| return UnknownVal(); |
| |
| const MemRegion* R = cast<loc::MemRegionVal>(&Array)->getRegion(); |
| const TypedRegion* ArrayR = dyn_cast<TypedRegion>(R); |
| |
| if (!ArrayR) |
| return UnknownVal(); |
| |
| // Strip off typedefs from the ArrayRegion's ValueType. |
| QualType T = ArrayR->getValueType(getContext())->getDesugaredType(); |
| ArrayType *AT = cast<ArrayType>(T); |
| T = AT->getElementType(); |
| |
| nonloc::ConcreteInt Idx(getBasicVals().getZeroWithPtrWidth(false)); |
| ElementRegion* ER = MRMgr.getElementRegion(T, Idx, ArrayR, getContext()); |
| |
| return loc::MemRegionVal(ER); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Pointer arithmetic. |
| //===----------------------------------------------------------------------===// |
| |
| SVal RegionStoreManager::EvalBinOp(const GRState *state, |
| BinaryOperator::Opcode Op, Loc L, NonLoc R, |
| QualType resultTy) { |
| // Assume the base location is MemRegionVal. |
| if (!isa<loc::MemRegionVal>(L)) |
| return UnknownVal(); |
| |
| const MemRegion* MR = cast<loc::MemRegionVal>(L).getRegion(); |
| const ElementRegion *ER = 0; |
| |
| switch (MR->getKind()) { |
| case MemRegion::SymbolicRegionKind: { |
| const SymbolicRegion *SR = cast<SymbolicRegion>(MR); |
| QualType T; |
| // If the SymbolicRegion was cast to another type, use that type. |
| if (const QualType *t = state->get<RegionCasts>(SR)) |
| T = *t; |
| else { |
| // Otherwise use the symbol's type. |
| SymbolRef Sym = SR->getSymbol(); |
| T = Sym->getType(getContext()); |
| } |
| |
| QualType EleTy = T->getAsPointerType()->getPointeeType(); |
| SVal ZeroIdx = ValMgr.makeZeroArrayIndex(); |
| ER = MRMgr.getElementRegion(EleTy, ZeroIdx, SR, getContext()); |
| break; |
| } |
| case MemRegion::AllocaRegionKind: { |
| // Get the alloca region's current cast type. |
| const AllocaRegion *AR = cast<AllocaRegion>(MR); |
| QualType T = *(state->get<RegionCasts>(AR)); |
| QualType EleTy = T->getAsPointerType()->getPointeeType(); |
| SVal ZeroIdx = ValMgr.makeZeroArrayIndex(); |
| ER = MRMgr.getElementRegion(EleTy, ZeroIdx, AR, getContext()); |
| break; |
| } |
| |
| case MemRegion::ElementRegionKind: { |
| ER = cast<ElementRegion>(MR); |
| break; |
| } |
| |
| // Not yet handled. |
| case MemRegion::VarRegionKind: |
| case MemRegion::StringRegionKind: |
| case MemRegion::CompoundLiteralRegionKind: |
| case MemRegion::FieldRegionKind: |
| case MemRegion::ObjCObjectRegionKind: |
| case MemRegion::ObjCIvarRegionKind: |
| return UnknownVal(); |
| |
| // TypedViewRegion will soon be removed. |
| case MemRegion::TypedViewRegionKind: |
| return UnknownVal(); |
| |
| case MemRegion::CodeTextRegionKind: |
| // Technically this can happen if people do funny things with casts. |
| return UnknownVal(); |
| |
| case MemRegion::MemSpaceRegionKind: |
| assert(0 && "Cannot perform pointer arithmetic on a MemSpace"); |
| return UnknownVal(); |
| |
| case MemRegion::BEG_DECL_REGIONS: |
| case MemRegion::END_DECL_REGIONS: |
| case MemRegion::BEG_TYPED_REGIONS: |
| case MemRegion::END_TYPED_REGIONS: |
| assert(0 && "Infeasible region"); |
| return UnknownVal(); |
| } |
| |
| SVal Idx = ER->getIndex(); |
| nonloc::ConcreteInt* Base = dyn_cast<nonloc::ConcreteInt>(&Idx); |
| nonloc::ConcreteInt* Offset = dyn_cast<nonloc::ConcreteInt>(&R); |
| |
| // Only support concrete integer indexes for now. |
| if (Base && Offset) { |
| // FIXME: For now, convert the signedness and bitwidth of offset in case |
| // they don't match. This can result from pointer arithmetic. In reality, |
| // we should figure out what are the proper semantics and implement them. |
| // |
| // This addresses the test case test/Analysis/ptr-arith.c |
| // |
| nonloc::ConcreteInt OffConverted(getBasicVals().Convert(Base->getValue(), |
| Offset->getValue())); |
| SVal NewIdx = Base->evalBinOp(ValMgr, Op, OffConverted); |
| const MemRegion* NewER = |
| MRMgr.getElementRegion(ER->getElementType(), NewIdx,ER->getSuperRegion(), |
| getContext()); |
| return ValMgr.makeLoc(NewER); |
| |
| } |
| |
| return UnknownVal(); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Loading values from regions. |
| //===----------------------------------------------------------------------===// |
| |
| static bool IsReinterpreted(QualType RTy, QualType UsedTy, ASTContext &Ctx) { |
| RTy = Ctx.getCanonicalType(RTy); |
| UsedTy = Ctx.getCanonicalType(UsedTy); |
| |
| if (RTy == UsedTy) |
| return false; |
| |
| return !(Loc::IsLocType(RTy) && Loc::IsLocType(UsedTy)); |
| } |
| |
| SVal RegionStoreManager::Retrieve(const GRState *state, Loc L, QualType T) { |
| |
| assert(!isa<UnknownVal>(L) && "location unknown"); |
| assert(!isa<UndefinedVal>(L) && "location undefined"); |
| |
| // FIXME: Is this even possible? Shouldn't this be treated as a null |
| // dereference at a higher level? |
| if (isa<loc::ConcreteInt>(L)) |
| return UndefinedVal(); |
| |
| const MemRegion *MR = cast<loc::MemRegionVal>(L).getRegion(); |
| |
| // FIXME: return symbolic value for these cases. |
| // Example: |
| // void f(int* p) { int x = *p; } |
| // char* p = alloca(); |
| // read(p); |
| // c = *p; |
| if (isa<AllocaRegion>(MR)) |
| return UnknownVal(); |
| |
| if (isa<SymbolicRegion>(MR)) { |
| ASTContext &Ctx = getContext(); |
| SVal idx = ValMgr.makeIntVal(0, Ctx.IntTy); |
| assert(!T.isNull()); |
| MR = MRMgr.getElementRegion(T, idx, MR, Ctx); |
| } |
| |
| // FIXME: Perhaps this method should just take a 'const MemRegion*' argument |
| // instead of 'Loc', and have the other Loc cases handled at a higher level. |
| const TypedRegion *R = cast<TypedRegion>(MR); |
| QualType RTy = R->getValueType(getContext()); |
| |
| // FIXME: We should eventually handle funny addressing. e.g.: |
| // |
| // int x = ...; |
| // int *p = &x; |
| // char *q = (char*) p; |
| // char c = *q; // returns the first byte of 'x'. |
| // |
| // Such funny addressing will occur due to layering of regions. |
| |
| ASTContext &Ctx = getContext(); |
| if (!T.isNull() && IsReinterpreted(RTy, T, Ctx)) { |
| SVal idx = ValMgr.makeIntVal(0, Ctx.IntTy); |
| R = MRMgr.getElementRegion(T, idx, R, Ctx); |
| RTy = T; |
| assert(RTy == R->getValueType(Ctx)); |
| } |
| |
| if (RTy->isStructureType()) |
| return RetrieveStruct(state, R); |
| |
| if (RTy->isArrayType()) |
| return RetrieveArray(state, R); |
| |
| // FIXME: handle Vector types. |
| if (RTy->isVectorType()) |
| return UnknownVal(); |
| |
| if (const FieldRegion* FR = dyn_cast<FieldRegion>(R)) |
| return RetrieveField(state, FR); |
| |
| if (const ElementRegion* ER = dyn_cast<ElementRegion>(R)) |
| return RetrieveElement(state, ER); |
| |
| RegionBindingsTy B = GetRegionBindings(state->getStore()); |
| RegionBindingsTy::data_type* V = B.lookup(R); |
| |
| // Check if the region has a binding. |
| if (V) |
| return *V; |
| |
| if (const ObjCIvarRegion *IVR = dyn_cast<ObjCIvarRegion>(R)) { |
| const MemRegion *SR = IVR->getSuperRegion(); |
| |
| // If the super region is 'self' then return the symbol representing |
| // the value of the ivar upon entry to the method. |
| if (SR == SelfRegion) { |
| // FIXME: Do we need to handle the case where the super region |
| // has a view? We want to canonicalize the bindings. |
| return ValMgr.getRegionValueSymbolVal(R); |
| } |
| |
| // Otherwise, we need a new symbol. For now return Unknown. |
| return UnknownVal(); |
| } |
| |
| // The location does not have a bound value. This means that it has |
| // the value it had upon its creation and/or entry to the analyzed |
| // function/method. These are either symbolic values or 'undefined'. |
| |
| // We treat function parameters as symbolic values. |
| if (const VarRegion* VR = dyn_cast<VarRegion>(R)) { |
| const VarDecl *VD = VR->getDecl(); |
| |
| if (VD == SelfDecl) |
| return loc::MemRegionVal(getSelfRegion(0)); |
| |
| if (VR->hasGlobalsOrParametersStorage()) |
| return ValMgr.getRegionValueSymbolValOrUnknown(VR, VD->getType()); |
| } |
| |
| if (R->hasHeapOrStackStorage()) { |
| // All stack variables are considered to have undefined values |
| // upon creation. All heap allocated blocks are considered to |
| // have undefined values as well unless they are explicitly bound |
| // to specific values. |
| return UndefinedVal(); |
| } |
| |
| // If the region is already cast to another type, use that type to create the |
| // symbol value. |
| if (const QualType *p = state->get<RegionCasts>(R)) { |
| QualType T = *p; |
| RTy = T->getAsPointerType()->getPointeeType(); |
| } |
| |
| // All other values are symbolic. |
| return ValMgr.getRegionValueSymbolValOrUnknown(R, RTy); |
| } |
| |
| SVal RegionStoreManager::RetrieveElement(const GRState* state, |
| const ElementRegion* R) { |
| // Check if the region has a binding. |
| RegionBindingsTy B = GetRegionBindings(state->getStore()); |
| if (const SVal* V = B.lookup(R)) |
| return *V; |
| |
| const MemRegion* superR = R->getSuperRegion(); |
| |
| // Check if the region is an element region of a string literal. |
| if (const StringRegion *StrR=dyn_cast<StringRegion>(superR)) { |
| const StringLiteral *Str = StrR->getStringLiteral(); |
| SVal Idx = R->getIndex(); |
| if (nonloc::ConcreteInt *CI = dyn_cast<nonloc::ConcreteInt>(&Idx)) { |
| int64_t i = CI->getValue().getSExtValue(); |
| char c; |
| if (i == Str->getByteLength()) |
| c = '\0'; |
| else |
| c = Str->getStrData()[i]; |
| return ValMgr.makeIntVal(c, getContext().CharTy); |
| } |
| } |
| |
| // Check if the super region has a default value. |
| if (const SVal *D = state->get<RegionDefaultValue>(superR)) { |
| if (D->hasConjuredSymbol()) |
| return ValMgr.getRegionValueSymbolVal(R); |
| else |
| return *D; |
| } |
| |
| // Check if the super region has a binding. |
| if (const SVal *V = B.lookup(superR)) { |
| if (SymbolRef parentSym = V->getAsSymbol()) |
| return ValMgr.getDerivedRegionValueSymbolVal(parentSym, R); |
| |
| // Other cases: give up. |
| return UnknownVal(); |
| } |
| |
| if (R->hasHeapStorage()) { |
| // FIXME: If the region has heap storage and we know nothing special |
| // about its bindings, should we instead return UnknownVal? Seems like |
| // we should only return UndefinedVal in the cases where we know the value |
| // will be undefined. |
| return UndefinedVal(); |
| } |
| |
| if (R->hasStackStorage() && !R->hasParametersStorage()) { |
| // Currently we don't reason specially about Clang-style vectors. Check |
| // if superR is a vector and if so return Unknown. |
| if (const TypedRegion *typedSuperR = dyn_cast<TypedRegion>(superR)) { |
| if (typedSuperR->getValueType(getContext())->isVectorType()) |
| return UnknownVal(); |
| } |
| |
| return UndefinedVal(); |
| } |
| |
| QualType Ty = R->getValueType(getContext()); |
| |
| // If the region is already cast to another type, use that type to create the |
| // symbol value. |
| if (const QualType *p = state->get<RegionCasts>(R)) |
| Ty = (*p)->getAsPointerType()->getPointeeType(); |
| |
| return ValMgr.getRegionValueSymbolValOrUnknown(R, Ty); |
| } |
| |
| SVal RegionStoreManager::RetrieveField(const GRState* state, |
| const FieldRegion* R) { |
| QualType Ty = R->getValueType(getContext()); |
| |
| // Check if the region has a binding. |
| RegionBindingsTy B = GetRegionBindings(state->getStore()); |
| if (const SVal* V = B.lookup(R)) |
| return *V; |
| |
| const MemRegion* superR = R->getSuperRegion(); |
| if (const SVal* D = state->get<RegionDefaultValue>(superR)) { |
| if (D->hasConjuredSymbol()) |
| return ValMgr.getRegionValueSymbolVal(R); |
| |
| if (D->isZeroConstant()) |
| return ValMgr.makeZeroVal(Ty); |
| |
| if (D->isUnknown()) |
| return *D; |
| |
| assert(0 && "Unknown default value"); |
| } |
| |
| // FIXME: Is this correct? Should it be UnknownVal? |
| if (R->hasHeapStorage()) |
| return UndefinedVal(); |
| |
| if (R->hasStackStorage() && !R->hasParametersStorage()) |
| return UndefinedVal(); |
| |
| // If the region is already cast to another type, use that type to create the |
| // symbol value. |
| if (const QualType *p = state->get<RegionCasts>(R)) { |
| QualType tmp = *p; |
| Ty = tmp->getAsPointerType()->getPointeeType(); |
| } |
| |
| // All other values are symbolic. |
| return ValMgr.getRegionValueSymbolValOrUnknown(R, Ty); |
| } |
| |
| SVal RegionStoreManager::RetrieveStruct(const GRState *state, |
| const TypedRegion* R){ |
| QualType T = R->getValueType(getContext()); |
| assert(T->isStructureType()); |
| |
| const RecordType* RT = T->getAsStructureType(); |
| RecordDecl* RD = RT->getDecl(); |
| assert(RD->isDefinition()); |
| |
| llvm::ImmutableList<SVal> StructVal = getBasicVals().getEmptySValList(); |
| |
| // FIXME: We shouldn't use a std::vector. If RecordDecl doesn't have a |
| // reverse iterator, we should implement one. |
| std::vector<FieldDecl *> Fields(RD->field_begin(), RD->field_end()); |
| |
| for (std::vector<FieldDecl *>::reverse_iterator Field = Fields.rbegin(), |
| FieldEnd = Fields.rend(); |
| Field != FieldEnd; ++Field) { |
| FieldRegion* FR = MRMgr.getFieldRegion(*Field, R); |
| QualType FTy = (*Field)->getType(); |
| SVal FieldValue = Retrieve(state, loc::MemRegionVal(FR), FTy); |
| StructVal = getBasicVals().consVals(FieldValue, StructVal); |
| } |
| |
| return ValMgr.makeCompoundVal(T, StructVal); |
| } |
| |
| SVal RegionStoreManager::RetrieveArray(const GRState *state, |
| const TypedRegion * R) { |
| |
| QualType T = R->getValueType(getContext()); |
| ConstantArrayType* CAT = cast<ConstantArrayType>(T.getTypePtr()); |
| |
| llvm::ImmutableList<SVal> ArrayVal = getBasicVals().getEmptySValList(); |
| llvm::APSInt Size(CAT->getSize(), false); |
| llvm::APSInt i = getBasicVals().getZeroWithPtrWidth(false); |
| |
| for (; i < Size; ++i) { |
| SVal Idx = ValMgr.makeIntVal(i); |
| ElementRegion* ER = MRMgr.getElementRegion(CAT->getElementType(), Idx, R, |
| getContext()); |
| QualType ETy = ER->getElementType(); |
| SVal ElementVal = Retrieve(state, loc::MemRegionVal(ER), ETy); |
| ArrayVal = getBasicVals().consVals(ElementVal, ArrayVal); |
| } |
| |
| return ValMgr.makeCompoundVal(T, ArrayVal); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Binding values to regions. |
| //===----------------------------------------------------------------------===// |
| |
| Store RegionStoreManager::Remove(Store store, Loc L) { |
| const MemRegion* R = 0; |
| |
| if (isa<loc::MemRegionVal>(L)) |
| R = cast<loc::MemRegionVal>(L).getRegion(); |
| |
| if (R) { |
| RegionBindingsTy B = GetRegionBindings(store); |
| return RBFactory.Remove(B, R).getRoot(); |
| } |
| |
| return store; |
| } |
| |
| const GRState *RegionStoreManager::Bind(const GRState *state, Loc L, SVal V) { |
| if (isa<loc::ConcreteInt>(L)) |
| return state; |
| |
| // If we get here, the location should be a region. |
| const MemRegion* R = cast<loc::MemRegionVal>(L).getRegion(); |
| |
| // Check if the region is a struct region. |
| if (const TypedRegion* TR = dyn_cast<TypedRegion>(R)) |
| if (TR->getValueType(getContext())->isStructureType()) |
| return BindStruct(state, TR, V); |
| |
| RegionBindingsTy B = GetRegionBindings(state->getStore()); |
| |
| B = RBFactory.Add(B, R, V); |
| |
| return state->makeWithStore(B.getRoot()); |
| } |
| |
| const GRState *RegionStoreManager::BindDecl(const GRState *state, |
| const VarDecl* VD, SVal InitVal) { |
| |
| QualType T = VD->getType(); |
| VarRegion* VR = MRMgr.getVarRegion(VD); |
| |
| if (T->isArrayType()) |
| return BindArray(state, VR, InitVal); |
| if (T->isStructureType()) |
| return BindStruct(state, VR, InitVal); |
| |
| return Bind(state, ValMgr.makeLoc(VR), InitVal); |
| } |
| |
| // FIXME: this method should be merged into Bind(). |
| const GRState * |
| RegionStoreManager::BindCompoundLiteral(const GRState *state, |
| const CompoundLiteralExpr* CL, |
| SVal V) { |
| |
| CompoundLiteralRegion* R = MRMgr.getCompoundLiteralRegion(CL); |
| return Bind(state, loc::MemRegionVal(R), V); |
| } |
| |
| const GRState *RegionStoreManager::BindArray(const GRState *state, |
| const TypedRegion* R, |
| SVal Init) { |
| |
| QualType T = R->getValueType(getContext()); |
| ConstantArrayType* CAT = cast<ConstantArrayType>(T.getTypePtr()); |
| QualType ElementTy = CAT->getElementType(); |
| |
| llvm::APSInt Size(CAT->getSize(), false); |
| llvm::APSInt i(llvm::APInt::getNullValue(Size.getBitWidth()), false); |
| |
| // Check if the init expr is a StringLiteral. |
| if (isa<loc::MemRegionVal>(Init)) { |
| const MemRegion* InitR = cast<loc::MemRegionVal>(Init).getRegion(); |
| const StringLiteral* S = cast<StringRegion>(InitR)->getStringLiteral(); |
| const char* str = S->getStrData(); |
| unsigned len = S->getByteLength(); |
| unsigned j = 0; |
| |
| // Copy bytes from the string literal into the target array. Trailing bytes |
| // in the array that are not covered by the string literal are initialized |
| // to zero. |
| for (; i < Size; ++i, ++j) { |
| if (j >= len) |
| break; |
| |
| SVal Idx = ValMgr.makeIntVal(i); |
| ElementRegion* ER = MRMgr.getElementRegion(ElementTy, Idx,R,getContext()); |
| |
| SVal V = ValMgr.makeIntVal(str[j], sizeof(char)*8, true); |
| state = Bind(state, loc::MemRegionVal(ER), V); |
| } |
| |
| return state; |
| } |
| |
| nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(Init); |
| nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end(); |
| |
| for (; i < Size; ++i, ++VI) { |
| // The init list might be shorter than the array length. |
| if (VI == VE) |
| break; |
| |
| SVal Idx = ValMgr.makeIntVal(i); |
| ElementRegion* ER = MRMgr.getElementRegion(ElementTy, Idx, R, getContext()); |
| |
| if (CAT->getElementType()->isStructureType()) |
| state = BindStruct(state, ER, *VI); |
| else |
| state = Bind(state, ValMgr.makeLoc(ER), *VI); |
| } |
| |
| // If the init list is shorter than the array length, set the array default |
| // value. |
| if (i < Size) { |
| if (ElementTy->isIntegerType()) { |
| SVal V = ValMgr.makeZeroVal(ElementTy); |
| state = setDefaultValue(state, R, V); |
| } |
| } |
| |
| return state; |
| } |
| |
| const GRState * |
| RegionStoreManager::BindStruct(const GRState *state, const TypedRegion* R, |
| SVal V) { |
| |
| if (!Features.supportsFields()) |
| return state; |
| |
| QualType T = R->getValueType(getContext()); |
| assert(T->isStructureType()); |
| |
| const RecordType* RT = T->getAsRecordType(); |
| RecordDecl* RD = RT->getDecl(); |
| |
| if (!RD->isDefinition()) |
| return state; |
| |
| // We may get non-CompoundVal accidentally due to imprecise cast logic. |
| // Ignore them and kill the field values. |
| if (V.isUnknown() || !isa<nonloc::CompoundVal>(V)) |
| return KillStruct(state, R); |
| |
| nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(V); |
| nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end(); |
| |
| RecordDecl::field_iterator FI, FE; |
| |
| for (FI = RD->field_begin(), FE = RD->field_end(); FI != FE; ++FI, ++VI) { |
| |
| if (VI == VE) |
| break; |
| |
| QualType FTy = (*FI)->getType(); |
| FieldRegion* FR = MRMgr.getFieldRegion(*FI, R); |
| |
| if (Loc::IsLocType(FTy) || FTy->isIntegerType()) |
| state = Bind(state, ValMgr.makeLoc(FR), *VI); |
| else if (FTy->isArrayType()) |
| state = BindArray(state, FR, *VI); |
| else if (FTy->isStructureType()) |
| state = BindStruct(state, FR, *VI); |
| } |
| |
| // There may be fewer values in the initialize list than the fields of struct. |
| if (FI != FE) |
| state = setDefaultValue(state, R, ValMgr.makeIntVal(0, false)); |
| |
| return state; |
| } |
| |
| const GRState *RegionStoreManager::KillStruct(const GRState *state, |
| const TypedRegion* R){ |
| |
| // Set the default value of the struct region to "unknown". |
| state = state->set<RegionDefaultValue>(R, UnknownVal()); |
| |
| // Remove all bindings for the subregions of the struct. |
| Store store = state->getStore(); |
| RegionBindingsTy B = GetRegionBindings(store); |
| for (RegionBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { |
| const MemRegion* R = I.getKey(); |
| if (const SubRegion* subRegion = dyn_cast<SubRegion>(R)) |
| if (subRegion->isSubRegionOf(R)) |
| store = Remove(store, ValMgr.makeLoc(subRegion)); |
| } |
| |
| return state->makeWithStore(store); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Region views. |
| //===----------------------------------------------------------------------===// |
| |
| const GRState *RegionStoreManager::AddRegionView(const GRState *state, |
| const MemRegion* View, |
| const MemRegion* Base) { |
| |
| // First, retrieve the region view of the base region. |
| const RegionViews* d = state->get<RegionViewMap>(Base); |
| RegionViews L = d ? *d : RVFactory.GetEmptySet(); |
| |
| // Now add View to the region view. |
| L = RVFactory.Add(L, View); |
| |
| // Create a new state with the new region view. |
| return state->set<RegionViewMap>(Base, L); |
| } |
| |
| const GRState *RegionStoreManager::RemoveRegionView(const GRState *state, |
| const MemRegion* View, |
| const MemRegion* Base) { |
| // Retrieve the region view of the base region. |
| const RegionViews* d = state->get<RegionViewMap>(Base); |
| |
| // If the base region has no view, return. |
| if (!d) |
| return state; |
| |
| // Remove the view. |
| return state->set<RegionViewMap>(Base, RVFactory.Remove(*d, View)); |
| } |
| |
| const GRState *RegionStoreManager::setCastType(const GRState *state, |
| const MemRegion* R, QualType T) { |
| // We do not record generic cast type, since we are using cast type to |
| // invlidate regions, and generic type is meaningless for invalidating |
| // regions. |
| // If the region already has a cast type before, that type is preserved. |
| // FIXME: is this the right thing to do? |
| if (isGenericPtr(getContext(), T)) |
| return state; |
| return state->set<RegionCasts>(R, T); |
| } |
| |
| const GRState *RegionStoreManager::setDefaultValue(const GRState *state, |
| const MemRegion* R, SVal V) { |
| return state->set<RegionDefaultValue>(R, V); |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // State pruning. |
| //===----------------------------------------------------------------------===// |
| |
| static void UpdateLiveSymbols(SVal X, SymbolReaper& SymReaper) { |
| if (loc::MemRegionVal *XR = dyn_cast<loc::MemRegionVal>(&X)) { |
| const MemRegion *R = XR->getRegion(); |
| |
| while (R) { |
| if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(R)) { |
| SymReaper.markLive(SR->getSymbol()); |
| return; |
| } |
| |
| if (const SubRegion *SR = dyn_cast<SubRegion>(R)) { |
| R = SR->getSuperRegion(); |
| continue; |
| } |
| |
| break; |
| } |
| |
| return; |
| } |
| |
| for (SVal::symbol_iterator SI=X.symbol_begin(), SE=X.symbol_end();SI!=SE;++SI) |
| SymReaper.markLive(*SI); |
| } |
| |
| Store RegionStoreManager::RemoveDeadBindings(const GRState *state, Stmt* Loc, |
| SymbolReaper& SymReaper, |
| llvm::SmallVectorImpl<const MemRegion*>& RegionRoots) |
| { |
| Store store = state->getStore(); |
| RegionBindingsTy B = GetRegionBindings(store); |
| |
| // Lazily constructed backmap from MemRegions to SubRegions. |
| typedef llvm::ImmutableSet<const MemRegion*> SubRegionsTy; |
| typedef llvm::ImmutableMap<const MemRegion*, SubRegionsTy> SubRegionsMapTy; |
| |
| // FIXME: As a future optimization we can modifiy BumpPtrAllocator to have |
| // the ability to reuse memory. This way we can keep TmpAlloc around as |
| // an instance variable of RegionStoreManager (avoiding repeated malloc |
| // overhead). |
| llvm::BumpPtrAllocator TmpAlloc; |
| |
| // Factory objects. |
| SubRegionsMapTy::Factory SubRegMapF(TmpAlloc); |
| SubRegionsTy::Factory SubRegF(TmpAlloc); |
| |
| // The backmap from regions to subregions. |
| SubRegionsMapTy SubRegMap = SubRegMapF.GetEmptyMap(); |
| |
| // Do a pass over the regions in the store. For VarRegions we check if |
| // the variable is still live and if so add it to the list of live roots. |
| // For other regions we populate our region backmap. |
| llvm::SmallVector<const MemRegion*, 10> IntermediateRoots; |
| |
| for (RegionBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { |
| IntermediateRoots.push_back(I.getKey()); |
| } |
| |
| while (!IntermediateRoots.empty()) { |
| const MemRegion* R = IntermediateRoots.back(); |
| IntermediateRoots.pop_back(); |
| |
| if (const VarRegion* VR = dyn_cast<VarRegion>(R)) { |
| if (SymReaper.isLive(Loc, VR->getDecl())) { |
| RegionRoots.push_back(VR); // This is a live "root". |
| } |
| } |
| else if (const SymbolicRegion* SR = dyn_cast<SymbolicRegion>(R)) { |
| if (SymReaper.isLive(SR->getSymbol())) |
| RegionRoots.push_back(SR); |
| } |
| else { |
| // Get the super region for R. |
| const MemRegion* superR = cast<SubRegion>(R)->getSuperRegion(); |
| |
| // Get the current set of subregions for SuperR. |
| const SubRegionsTy* SRptr = SubRegMap.lookup(superR); |
| SubRegionsTy SRs = SRptr ? *SRptr : SubRegF.GetEmptySet(); |
| |
| // Add R to the subregions of SuperR. |
| SubRegMap = SubRegMapF.Add(SubRegMap, superR, SubRegF.Add(SRs, R)); |
| |
| // Super region may be VarRegion or subregion of another VarRegion. Add it |
| // to the work list. |
| if (isa<SubRegion>(superR)) |
| IntermediateRoots.push_back(superR); |
| } |
| } |
| |
| // Process the worklist of RegionRoots. This performs a "mark-and-sweep" |
| // of the store. We want to find all live symbols and dead regions. |
| llvm::SmallPtrSet<const MemRegion*, 10> Marked; |
| |
| while (!RegionRoots.empty()) { |
| // Dequeue the next region on the worklist. |
| const MemRegion* R = RegionRoots.back(); |
| RegionRoots.pop_back(); |
| |
| // Check if we have already processed this region. |
| if (Marked.count(R)) continue; |
| |
| // Mark this region as processed. This is needed for termination in case |
| // a region is referenced more than once. |
| Marked.insert(R); |
| |
| // Mark the symbol for any live SymbolicRegion as "live". This means we |
| // should continue to track that symbol. |
| if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(R)) |
| SymReaper.markLive(SymR->getSymbol()); |
| |
| // Get the data binding for R (if any). |
| RegionBindingsTy::data_type* Xptr = B.lookup(R); |
| if (Xptr) { |
| SVal X = *Xptr; |
| UpdateLiveSymbols(X, SymReaper); // Update the set of live symbols. |
| |
| // If X is a region, then add it to the RegionRoots. |
| if (const MemRegion *RX = X.getAsRegion()) { |
| RegionRoots.push_back(RX); |
| |
| // Mark the super region of the RX as live. |
| // e.g.: int x; char *y = (char*) &x; if (*y) ... |
| // 'y' => element region. 'x' is its super region. |
| // We only add one level super region for now. |
| // FIXME: maybe multiple level of super regions should be added. |
| if (const SubRegion *SR = dyn_cast<SubRegion>(RX)) { |
| RegionRoots.push_back(SR->getSuperRegion()); |
| } |
| } |
| } |
| |
| // Get the subregions of R. These are RegionRoots as well since they |
| // represent values that are also bound to R. |
| const SubRegionsTy* SRptr = SubRegMap.lookup(R); |
| if (!SRptr) continue; |
| SubRegionsTy SR = *SRptr; |
| |
| for (SubRegionsTy::iterator I=SR.begin(), E=SR.end(); I!=E; ++I) |
| RegionRoots.push_back(*I); |
| |
| } |
| |
| // We have now scanned the store, marking reachable regions and symbols |
| // as live. We now remove all the regions that are dead from the store |
| // as well as update DSymbols with the set symbols that are now dead. |
| for (RegionBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) { |
| const MemRegion* R = I.getKey(); |
| // If this region live? Is so, none of its symbols are dead. |
| if (Marked.count(R)) |
| continue; |
| |
| // Remove this dead region from the store. |
| store = Remove(store, ValMgr.makeLoc(R)); |
| |
| // Mark all non-live symbols that this region references as dead. |
| if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(R)) |
| SymReaper.maybeDead(SymR->getSymbol()); |
| |
| SVal X = I.getData(); |
| SVal::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end(); |
| for (; SI != SE; ++SI) SymReaper.maybeDead(*SI); |
| } |
| |
| return store; |
| } |
| |
| //===----------------------------------------------------------------------===// |
| // Utility methods. |
| //===----------------------------------------------------------------------===// |
| |
| void RegionStoreManager::print(Store store, llvm::raw_ostream& OS, |
| const char* nl, const char *sep) { |
| RegionBindingsTy B = GetRegionBindings(store); |
| OS << "Store:" << nl; |
| |
| for (RegionBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) |
| OS << ' ' << I.getKey() << " : " << I.getData() << nl; |
| } |