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//== Store.cpp - Interface for maps from Locations to Values ----*- C++ -*--==//
// The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
// This file defined the types Store and StoreManager.
#include "clang/Checker/PathSensitive/Store.h"
#include "clang/Checker/PathSensitive/GRState.h"
#include "clang/AST/CharUnits.h"
using namespace clang;
StoreManager::StoreManager(GRStateManager &stateMgr)
: ValMgr(stateMgr.getValueManager()), StateMgr(stateMgr),
MRMgr(ValMgr.getRegionManager()), Ctx(stateMgr.getContext()) {}
const MemRegion *StoreManager::MakeElementRegion(const MemRegion *Base,
QualType EleTy, uint64_t index) {
SVal idx = ValMgr.makeArrayIndex(index);
return MRMgr.getElementRegion(EleTy, idx, Base, ValMgr.getContext());
// FIXME: Merge with the implementation of the same method in MemRegion.cpp
static bool IsCompleteType(ASTContext &Ctx, QualType Ty) {
if (const RecordType *RT = Ty->getAs<RecordType>()) {
const RecordDecl *D = RT->getDecl();
if (!D->getDefinition())
return false;
return true;
const MemRegion *StoreManager::CastRegion(const MemRegion *R, QualType CastToTy) {
ASTContext& Ctx = StateMgr.getContext();
// Handle casts to Objective-C objects.
if (CastToTy->isObjCObjectPointerType())
return R->StripCasts();
if (CastToTy->isBlockPointerType()) {
// FIXME: We may need different solutions, depending on the symbol
// involved. Blocks can be casted to/from 'id', as they can be treated
// as Objective-C objects. This could possibly be handled by enhancing
// our reasoning of downcasts of symbolic objects.
if (isa<CodeTextRegion>(R) || isa<SymbolicRegion>(R))
return R;
// We don't know what to make of it. Return a NULL region, which
// will be interpretted as UnknownVal.
return NULL;
// Now assume we are casting from pointer to pointer. Other cases should
// already be handled.
QualType PointeeTy = CastToTy->getAs<PointerType>()->getPointeeType();
QualType CanonPointeeTy = Ctx.getCanonicalType(PointeeTy);
// Handle casts to void*. We just pass the region through.
if (CanonPointeeTy.getLocalUnqualifiedType() == Ctx.VoidTy)
return R;
// Handle casts from compatible types.
if (R->isBoundable())
if (const TypedRegion *TR = dyn_cast<TypedRegion>(R)) {
QualType ObjTy = Ctx.getCanonicalType(TR->getValueType(Ctx));
if (CanonPointeeTy == ObjTy)
return R;
// Process region cast according to the kind of the region being cast.
switch (R->getKind()) {
case MemRegion::CXXThisRegionKind:
case MemRegion::GenericMemSpaceRegionKind:
case MemRegion::StackLocalsSpaceRegionKind:
case MemRegion::StackArgumentsSpaceRegionKind:
case MemRegion::HeapSpaceRegionKind:
case MemRegion::UnknownSpaceRegionKind:
case MemRegion::GlobalsSpaceRegionKind: {
assert(0 && "Invalid region cast");
case MemRegion::FunctionTextRegionKind:
case MemRegion::BlockTextRegionKind:
case MemRegion::BlockDataRegionKind: {
// CodeTextRegion should be cast to only a function or block pointer type,
// although they can in practice be casted to anything, e.g, void*, char*,
// etc.
// Just return the region.
return R;
case MemRegion::StringRegionKind:
// FIXME: Need to handle arbitrary downcasts.
case MemRegion::SymbolicRegionKind:
case MemRegion::AllocaRegionKind:
case MemRegion::CompoundLiteralRegionKind:
case MemRegion::FieldRegionKind:
case MemRegion::ObjCIvarRegionKind:
case MemRegion::VarRegionKind:
case MemRegion::CXXObjectRegionKind:
return MakeElementRegion(R, PointeeTy);
case MemRegion::ElementRegionKind: {
// If we are casting from an ElementRegion to another type, the
// algorithm is as follows:
// (1) Compute the "raw offset" of the ElementRegion from the
// base region. This is done by calling 'getAsRawOffset()'.
// (2a) If we get a 'RegionRawOffset' after calling
// 'getAsRawOffset()', determine if the absolute offset
// can be exactly divided into chunks of the size of the
// casted-pointee type. If so, create a new ElementRegion with
// the pointee-cast type as the new ElementType and the index
// being the offset divded by the chunk size. If not, create
// a new ElementRegion at offset 0 off the raw offset region.
// (2b) If we don't a get a 'RegionRawOffset' after calling
// 'getAsRawOffset()', it means that we are at offset 0.
// FIXME: Handle symbolic raw offsets.
const ElementRegion *elementR = cast<ElementRegion>(R);
const RegionRawOffset &rawOff = elementR->getAsRawOffset();
const MemRegion *baseR = rawOff.getRegion();
// If we cannot compute a raw offset, throw up our hands and return
// a NULL MemRegion*.
if (!baseR)
return NULL;
CharUnits off = CharUnits::fromQuantity(rawOff.getByteOffset());
if (off.isZero()) {
// Edge case: we are at 0 bytes off the beginning of baseR. We
// check to see if type we are casting to is the same as the base
// region. If so, just return the base region.
if (const TypedRegion *TR = dyn_cast<TypedRegion>(baseR)) {
QualType ObjTy = Ctx.getCanonicalType(TR->getValueType(Ctx));
QualType CanonPointeeTy = Ctx.getCanonicalType(PointeeTy);
if (CanonPointeeTy == ObjTy)
return baseR;
// Otherwise, create a new ElementRegion at offset 0.
return MakeElementRegion(baseR, PointeeTy);
// We have a non-zero offset from the base region. We want to determine
// if the offset can be evenly divided by sizeof(PointeeTy). If so,
// we create an ElementRegion whose index is that value. Otherwise, we
// create two ElementRegions, one that reflects a raw offset and the other
// that reflects the cast.
// Compute the index for the new ElementRegion.
int64_t newIndex = 0;
const MemRegion *newSuperR = 0;
// We can only compute sizeof(PointeeTy) if it is a complete type.
if (IsCompleteType(Ctx, PointeeTy)) {
// Compute the size in **bytes**.
CharUnits pointeeTySize = Ctx.getTypeSizeInChars(PointeeTy);
// Is the offset a multiple of the size? If so, we can layer the
// ElementRegion (with elementType == PointeeTy) directly on top of
// the base region.
if (off % pointeeTySize == 0) {
newIndex = off / pointeeTySize;
newSuperR = baseR;
if (!newSuperR) {
// Create an intermediate ElementRegion to represent the raw byte.
// This will be the super region of the final ElementRegion.
newSuperR = MakeElementRegion(baseR, Ctx.CharTy, off.getQuantity());
return MakeElementRegion(newSuperR, PointeeTy, newIndex);
assert(0 && "unreachable");
return 0;
/// CastRetrievedVal - Used by subclasses of StoreManager to implement
/// implicit casts that arise from loads from regions that are reinterpreted
/// as another region.
SVal StoreManager::CastRetrievedVal(SVal V, const TypedRegion *R,
QualType castTy, bool performTestOnly) {
if (castTy.isNull())
return V;
ASTContext &Ctx = ValMgr.getContext();
if (performTestOnly) {
// Automatically translate references to pointers.
QualType T = R->getValueType(Ctx);
if (const ReferenceType *RT = T->getAs<ReferenceType>())
T = Ctx.getPointerType(RT->getPointeeType());
assert(ValMgr.getContext().hasSameUnqualifiedType(castTy, T));
return V;
if (const Loc *L = dyn_cast<Loc>(&V))
return ValMgr.getSValuator().EvalCastL(*L, castTy);
else if (const NonLoc *NL = dyn_cast<NonLoc>(&V))
return ValMgr.getSValuator().EvalCastNL(*NL, castTy);
return V;
Store StoreManager::InvalidateRegions(Store store,
const MemRegion * const *I,
const MemRegion * const *End,
const Expr *E, unsigned Count,
InvalidatedSymbols *IS) {
for ( ; I != End ; ++I)
store = InvalidateRegion(store, *I, E, Count, IS);
return store;
SVal StoreManager::getLValueFieldOrIvar(const Decl* D, SVal Base) {
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();
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;
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 StoreManager::getLValueElement(QualType elementType, SVal Offset,
SVal Base) {
// 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);
// Convert the offset to the appropriate size and signedness.
Offset = ValMgr.convertToArrayIndex(Offset);
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.
return loc::MemRegionVal(MRMgr.getElementRegion(elementType, Offset,
BaseRegion, Ctx));
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();
// Compute the new index.
SVal NewIdx = nonloc::ConcreteInt(
ValMgr.getBasicValueFactory().getValue(BaseIdxI + OffI));
// Construct the new ElementRegion.
const MemRegion *ArrayR = ElemR->getSuperRegion();
return loc::MemRegionVal(MRMgr.getElementRegion(elementType, NewIdx, ArrayR,