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llvm-project/clang/lib/Analysis/RegionStore.cpp

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//== 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 "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;
//===----------------------------------------------------------------------===//
// 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::ImmutableList<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; }
};
}
//===----------------------------------------------------------------------===//
// 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; }
};
}
//===----------------------------------------------------------------------===//
// Region "killsets".
//===----------------------------------------------------------------------===//
//
// RegionStore lazily adds value bindings to regions when the analyzer
// handles assignment statements. Killsets track which default values have
// been killed, thus distinguishing between "unknown" values and default
// values.
//
namespace { class VISIBILITY_HIDDEN RegionKills {}; }
static int RegionKillsIndex = 0;
namespace clang {
template<> struct GRStateTrait<RegionKills>
: public GRStatePartialTrait< llvm::ImmutableSet<const MemRegion*> > {
static void* GDMIndex() { return &RegionKillsIndex; }
};
}
//===----------------------------------------------------------------------===//
// Regions with default values of '0'.
//===----------------------------------------------------------------------===//
//
// This GDM entry tracks what regions have a default value of 0 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 RegionStoreManager : public StoreManager {
RegionBindingsTy::Factory RBFactory;
RegionViews::Factory RVFactory;
GRStateManager& StateMgr;
MemRegionManager MRMgr;
public:
RegionStoreManager(GRStateManager& mgr)
: RBFactory(mgr.getAllocator()),
RVFactory(mgr.getAllocator()),
StateMgr(mgr),
MRMgr(StateMgr.getAllocator()) {}
virtual ~RegionStoreManager() {}
MemRegionManager& getRegionManager() { return MRMgr; }
const GRState* BindCompoundLiteral(const GRState* St,
const CompoundLiteralExpr* CL, SVal V);
SVal getLValueString(const GRState* St, const StringLiteral* S);
SVal getLValueCompoundLiteral(const GRState* St, const CompoundLiteralExpr*);
SVal getLValueVar(const GRState* St, const VarDecl* VD);
SVal getLValueIvar(const GRState* St, const ObjCIvarDecl* D, SVal Base);
SVal getLValueField(const GRState* St, SVal Base, const FieldDecl* D);
SVal getLValueElement(const GRState* St, SVal Base, SVal Offset);
SVal getSizeInElements(const GRState* St, const MemRegion* R);
SVal ArrayToPointer(SVal Array);
/// CastRegion - Used by GRExprEngine::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.
CastResult CastRegion(const GRState* state, const MemRegion* R,
QualType CastToTy);
/// 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());
const GRState* Bind(const GRState* St, Loc LV, SVal V);
Store Remove(Store store, Loc LV);
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) {
assert (false && "Not implemented.");
return 0;
}
/// RemoveDeadBindings - Scans the RegionStore of 'state' for dead values.
/// It returns a new Store with these values removed, and populates LSymbols
// and DSymbols with the known set of live and dead symbols respectively.
Store RemoveDeadBindings(const GRState* state, Stmt* Loc,
const LiveVariables& Live,
llvm::SmallVectorImpl<const MemRegion*>& RegionRoots,
LiveSymbolsTy& LSymbols, DeadSymbolsTy& DSymbols);
void UpdateLiveSymbols(SVal X, LiveSymbolsTy& LSymbols);
const GRState* BindDecl(const GRState* St, const VarDecl* VD, SVal InitVal);
const GRState* BindDeclWithNoInit(const GRState* St, const VarDecl* VD) {
return St;
}
const GRState* setExtent(const GRState* St, const MemRegion* R, SVal Extent);
static inline RegionBindingsTy GetRegionBindings(Store store) {
return RegionBindingsTy(static_cast<const RegionBindingsTy::TreeTy*>(store));
}
void print(Store store, std::ostream& Out, const char* nl, const char *sep);
void iterBindings(Store store, BindingsHandler& f) {
// FIXME: Implement.
}
private:
Loc getVarLoc(const VarDecl* VD) {
return loc::MemRegionVal(MRMgr.getVarRegion(VD));
}
const GRState* BindArray(const GRState* St, const TypedRegion* R, SVal V);
/// 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);
const GRState* BindStruct(const GRState* St, const TypedRegion* R, SVal V);
// Utility methods.
BasicValueFactory& getBasicVals() { return StateMgr.getBasicVals(); }
ASTContext& getContext() { return StateMgr.getContext(); }
SymbolManager& getSymbolManager() { return StateMgr.getSymbolManager(); }
const GRState* AddRegionView(const GRState* St,
const MemRegion* View, const MemRegion* Base);
};
} // end anonymous namespace
StoreManager* clang::CreateRegionStoreManager(GRStateManager& StMgr) {
return new RegionStoreManager(StMgr);
}
SVal RegionStoreManager::getLValueString(const GRState* St,
const StringLiteral* S) {
return loc::MemRegionVal(MRMgr.getStringRegion(S));
}
SVal RegionStoreManager::getLValueVar(const GRState* St, const VarDecl* VD) {
return loc::MemRegionVal(MRMgr.getVarRegion(VD));
}
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 UnknownVal();
}
SVal RegionStoreManager::getLValueField(const GRState* St, SVal Base,
const FieldDecl* 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::SymbolValKind:
BaseR = MRMgr.getSymbolicRegion(cast<loc::SymbolVal>(&BaseL)->getSymbol());
break;
case loc::GotoLabelKind:
case loc::FuncValKind:
// 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;
}
return loc::MemRegionVal(MRMgr.getFieldRegion(D, BaseR));
}
SVal RegionStoreManager::getLValueElement(const GRState* St,
SVal Base, SVal Offset) {
if (Base.isUnknownOrUndef())
return Base;
if (isa<loc::SymbolVal>(Base))
return Base;
loc::MemRegionVal& BaseL = cast<loc::MemRegionVal>(Base);
// Pointer of any type can be cast and used as array base. We do not support
// that case yet.
if (!isa<ElementRegion>(BaseL.getRegion())) {
// Record what we have seen in real code.
assert(isa<FieldRegion>(BaseL.getRegion()));
return UnknownVal();
}
// We expect BaseR is an ElementRegion, not a base VarRegion.
const ElementRegion* ElemR = cast<ElementRegion>(BaseL.getRegion());
SVal Idx = ElemR->getIndex();
nonloc::ConcreteInt *CI1, *CI2;
// Only handle integer indices for now.
if ((CI1 = dyn_cast<nonloc::ConcreteInt>(&Idx)) &&
(CI2 = dyn_cast<nonloc::ConcreteInt>(&Offset))) {
// Temporary SVal to hold a potential signed and extended APSInt.
SVal SignedInt;
// Index might be unsigned. We have to convert it to signed. It might also
// be less wide than the size. We have to extend it.
if (CI2->getValue().isUnsigned() ||
CI2->getValue().getBitWidth() < CI1->getValue().getBitWidth()) {
llvm::APSInt SI = CI2->getValue();
if (CI2->getValue().getBitWidth() < CI1->getValue().getBitWidth())
SI.extend(CI1->getValue().getBitWidth());
SI.setIsSigned(true);
SignedInt = nonloc::ConcreteInt(getBasicVals().getValue(SI));
CI2 = cast<nonloc::ConcreteInt>(&SignedInt);
}
SVal NewIdx = CI1->EvalBinOp(getBasicVals(), BinaryOperator::Add, *CI2);
return loc::MemRegionVal(MRMgr.getElementRegion(NewIdx,
ElemR->getArrayRegion()));
}
return UnknownVal();
}
SVal RegionStoreManager::getSizeInElements(const GRState* St,
const MemRegion* R) {
if (const VarRegion* VR = dyn_cast<VarRegion>(R)) {
// Get the type of the variable.
QualType T = VR->getRValueType(getContext());
// It must be of array type.
const ConstantArrayType* CAT = cast<ConstantArrayType>(T.getTypePtr());
// return the size as signed integer.
return NonLoc::MakeVal(getBasicVals(), CAT->getSize(), false);
}
if (const StringRegion* SR = dyn_cast<StringRegion>(R)) {
const StringLiteral* Str = SR->getStringLiteral();
// We intentionally made the size value signed because it participates in
// operations with signed indices.
return NonLoc::MakeVal(getBasicVals(), Str->getByteLength() + 1, false);
}
if (const AnonTypedRegion* ATR = dyn_cast<AnonTypedRegion>(R)) {
GRStateRef state(St, StateMgr);
// Get the size of the super region in bytes.
const SVal* Extent = state.get<RegionExtents>(ATR->getSuperRegion());
assert(Extent && "region extent not exist");
// Assume it's ConcreteInt for now.
llvm::APSInt SSize = cast<nonloc::ConcreteInt>(*Extent).getValue();
// Get the size of the element in bits.
QualType LvT = ATR->getLValueType(getContext());
QualType ElemTy = cast<PointerType>(LvT.getTypePtr())->getPointeeType();
uint64_t X = getContext().getTypeSize(ElemTy);
const llvm::APSInt& ESize = getBasicVals().getValue(X, SSize.getBitWidth(),
false);
// Calculate the number of elements.
// FIXME: What do we do with signed-ness problem? Shall we make all APSInts
// signed?
if (SSize.isUnsigned())
SSize.setIsSigned(true);
// FIXME: move this operation into BasicVals.
const llvm::APSInt S =
(SSize * getBasicVals().getValue(8, SSize.getBitWidth(), false)) / ESize;
return NonLoc::MakeVal(getBasicVals(), S);
}
if (const FieldRegion* FR = dyn_cast<FieldRegion>(R)) {
// FIXME: Unsupported yet.
FR = 0;
return UnknownVal();
}
assert(0 && "Other regions are not supported yet.");
}
// Cast 'pointer to array' to 'pointer to the first element of array'.
SVal RegionStoreManager::ArrayToPointer(SVal Array) {
if (Array.isUnknownOrUndef())
return 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();
nonloc::ConcreteInt Idx(getBasicVals().getZeroWithPtrWidth(false));
ElementRegion* ER = MRMgr.getElementRegion(Idx, ArrayR);
return loc::MemRegionVal(ER);
}
StoreManager::CastResult
RegionStoreManager::CastRegion(const GRState* state, const MemRegion* R,
QualType CastToTy) {
// Return the same region if the region types are compatible.
if (const TypedRegion* TR = dyn_cast<TypedRegion>(R)) {
ASTContext& Ctx = StateMgr.getContext();
QualType Ta = Ctx.getCanonicalType(TR->getLValueType(Ctx));
QualType Tb = Ctx.getCanonicalType(CastToTy);
if (Ta == Tb)
return CastResult(state, R);
}
const MemRegion* ViewR = MRMgr.getAnonTypedRegion(CastToTy, R);
return CastResult(AddRegionView(state, ViewR, R), ViewR);
}
SVal RegionStoreManager::Retrieve(const GRState* St, Loc L, QualType T) {
assert(!isa<UnknownVal>(L) && "location unknown");
assert(!isa<UndefinedVal>(L) && "location undefined");
if (isa<loc::SymbolVal>(L))
return UnknownVal();
if (isa<loc::ConcreteInt>(L))
return UndefinedVal();
if (isa<loc::FuncVal>(L))
return L;
const MemRegion* R = cast<loc::MemRegionVal>(L).getRegion();
assert(R && "bad region");
if (const TypedRegion* TR = dyn_cast<TypedRegion>(R))
if (TR->getRValueType(getContext())->isStructureType())
return RetrieveStruct(St, TR);
RegionBindingsTy B = GetRegionBindings(St->getStore());
RegionBindingsTy::data_type* V = B.lookup(R);
// Check if the region has a binding.
if (V)
return *V;
// Check if the region is in killset.
GRStateRef state(St, StateMgr);
if (state.contains<RegionKills>(R))
return UnknownVal();
// The location is not initialized.
// We treat parameters as symbolic values.
if (const VarRegion* VR = dyn_cast<VarRegion>(R))
if (isa<ParmVarDecl>(VR->getDecl()))
return SVal::MakeSymbolValue(getSymbolManager(), VR,
VR->getRValueType(getContext()));
if (MRMgr.onStack(R) || MRMgr.onHeap(R))
return UndefinedVal();
else
return SVal::MakeSymbolValue(getSymbolManager(), R,
cast<TypedRegion>(R)->getRValueType(getContext()));
// FIXME: consider default values for elements and fields.
}
SVal RegionStoreManager::RetrieveStruct(const GRState* St,const TypedRegion* R){
Store store = St->getStore();
GRStateRef state(St, StateMgr);
// FIXME: Verify we want getRValueType instead of getLValueType.
QualType T = R->getRValueType(getContext());
assert(T->isStructureType());
const RecordType* RT = cast<RecordType>(T.getTypePtr());
RecordDecl* RD = RT->getDecl();
assert(RD->isDefinition());
llvm::ImmutableList<SVal> StructVal = getBasicVals().getEmptySValList();
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);
RegionBindingsTy B = GetRegionBindings(store);
RegionBindingsTy::data_type* data = B.lookup(FR);
SVal FieldValue;
if (data)
FieldValue = *data;
else if (state.contains<RegionKills>(FR))
FieldValue = UnknownVal();
else {
if (MRMgr.onStack(FR) || MRMgr.onHeap(FR))
FieldValue = UndefinedVal();
else
FieldValue = SVal::MakeSymbolValue(getSymbolManager(), FR,
FR->getRValueType(getContext()));
}
StructVal = getBasicVals().consVals(FieldValue, StructVal);
}
return NonLoc::MakeCompoundVal(T, StructVal, getBasicVals());
}
const GRState* RegionStoreManager::Bind(const GRState* St, Loc L, SVal V) {
// Currently we don't bind value to symbolic location. But if the logic is
// made clear, we might change this decision.
if (isa<loc::SymbolVal>(L))
return St;
// If we get here, the location should be a region.
const MemRegion* R = cast<loc::MemRegionVal>(L).getRegion();
assert(R);
// Check if the region is a struct region.
if (const TypedRegion* TR = dyn_cast<TypedRegion>(R))
// FIXME: Verify we want getRValueType().
if (TR->getRValueType(getContext())->isStructureType())
return BindStruct(St, TR, V);
Store store = St->getStore();
RegionBindingsTy B = GetRegionBindings(store);
if (V.isUnknown()) {
// Remove the binding.
store = RBFactory.Remove(B, R).getRoot();
// Add the region to the killset.
GRStateRef state(St, StateMgr);
St = state.add<RegionKills>(R);
}
else
store = RBFactory.Add(B, R, V).getRoot();
return StateMgr.MakeStateWithStore(St, store);
}
Store RegionStoreManager::Remove(Store store, Loc L) {
RegionBindingsTy B = GetRegionBindings(store);
const MemRegion* R = cast<loc::MemRegionVal>(L).getRegion();
assert(R);
return RBFactory.Remove(B, R).getRoot();
}
const GRState* RegionStoreManager::BindDecl(const GRState* St,
const VarDecl* VD, SVal InitVal) {
// All static variables are treated as symbolic values.
if (VD->hasGlobalStorage())
return St;
// Process local variables.
QualType T = VD->getType();
VarRegion* VR = MRMgr.getVarRegion(VD);
if (Loc::IsLocType(T) || T->isIntegerType())
return Bind(St, Loc::MakeVal(VR), InitVal);
else if (T->isArrayType())
return BindArray(St, VR, InitVal);
else if (T->isStructureType())
return BindStruct(St, VR, InitVal);
// Other types of variable are not supported yet.
return St;
}
// FIXME: this method should be merged into Bind().
const GRState*
RegionStoreManager::BindCompoundLiteral(const GRState* St,
const CompoundLiteralExpr* CL, SVal V) {
CompoundLiteralRegion* R = MRMgr.getCompoundLiteralRegion(CL);
return Bind(St, loc::MemRegionVal(R), V);
}
const GRState* RegionStoreManager::setExtent(const GRState* St,
const MemRegion* R, SVal Extent) {
GRStateRef state(St, StateMgr);
return state.set<RegionExtents>(R, Extent);
}
void RegionStoreManager::UpdateLiveSymbols(SVal X, LiveSymbolsTy& LSymbols) {
for (SVal::symbol_iterator SI=X.symbol_begin(),SE=X.symbol_end();SI!=SE;++SI)
LSymbols.insert(*SI);
}
Store RegionStoreManager::RemoveDeadBindings(const GRState* state, Stmt* Loc,
const LiveVariables& Live,
llvm::SmallVectorImpl<const MemRegion*>& RegionRoots,
LiveSymbolsTy& LSymbols, DeadSymbolsTy& DSymbols) {
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.
for (RegionBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) {
const MemRegion* R = I.getKey();
if (const VarRegion* VR = dyn_cast<VarRegion>(R)) {
if (Live.isLive(Loc, VR->getDecl()))
RegionRoots.push_back(VR); // This is a live "root".
}
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 SR = SRptr ? *SRptr : SubRegF.GetEmptySet();
// Add R to the subregions of SuperR.
SubRegMap = SubRegMapF.Add(SubRegMap, SuperR, SubRegF.Add(SR, R));
// Finally, check if SuperR is a VarRegion. We need to do this
// to also mark SuperR as a root (as it may not have a value directly
// bound to it in the store).
if (const VarRegion* VR = dyn_cast<VarRegion>(SuperR)) {
if (Live.isLive(Loc, VR->getDecl()))
RegionRoots.push_back(VR); // This is a live "root".
}
}
}
// 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))
LSymbols.insert(SymR->getSymbol());
// Get the data binding for R (if any).
RegionBindingsTy::data_type* Xptr = B.lookup(R);
if (Xptr) {
SVal X = *Xptr;
UpdateLiveSymbols(X, LSymbols); // Update the set of live symbols.
// If X is a region, then add it the RegionRoots.
if (loc::MemRegionVal* RegionX = dyn_cast<loc::MemRegionVal>(&X))
RegionRoots.push_back(RegionX->getRegion());
}
// 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, Loc::MakeVal(R));
// Mark all non-live symbols that this region references as dead.
if (const SymbolicRegion* SymR = dyn_cast<SymbolicRegion>(R)) {
SymbolRef Sym = SymR->getSymbol();
if (!LSymbols.count(Sym)) DSymbols.insert(Sym);
}
SVal X = I.getData();
SVal::symbol_iterator SI = X.symbol_begin(), SE = X.symbol_end();
for (; SI != SE; ++SI) { if (!LSymbols.count(*SI)) DSymbols.insert(*SI); }
}
return store;
}
void RegionStoreManager::print(Store store, std::ostream& Out,
const char* nl, const char *sep) {
llvm::raw_os_ostream OS(Out);
RegionBindingsTy B = GetRegionBindings(store);
OS << "Store:" << nl;
for (RegionBindingsTy::iterator I = B.begin(), E = B.end(); I != E; ++I) {
OS << ' '; I.getKey()->print(OS); OS << " : ";
I.getData().print(OS); OS << nl;
}
}
const GRState* RegionStoreManager::BindArray(const GRState* St,
const TypedRegion* R, SVal Init) {
// FIXME: Verify we should use getLValueType or getRValueType.
QualType T = R->getRValueType(getContext());
assert(T->isArrayType());
// When we are binding the whole array, it always has default value 0.
GRStateRef state(St, StateMgr);
// St = state.set<RegionDefaultValue>(R, NonLoc::MakeVal(getBasicVals(), 0,
// false));
Store store = St->getStore();
ConstantArrayType* CAT = cast<ConstantArrayType>(T.getTypePtr());
llvm::APSInt Size(CAT->getSize(), false);
llvm::APSInt i = getBasicVals().getZeroWithPtrWidth(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 = NonLoc::MakeVal(getBasicVals(), i);
ElementRegion* ER = MRMgr.getElementRegion(Idx, R);
SVal V = NonLoc::MakeVal(getBasicVals(), str[j], sizeof(char)*8, true);
St = Bind(St, loc::MemRegionVal(ER), V);
}
return StateMgr.MakeStateWithStore(St, store);
}
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 decl.
if (VI == VE)
break;
SVal Idx = NonLoc::MakeVal(getBasicVals(), i);
ElementRegion* ER = MRMgr.getElementRegion(Idx, R);
if (CAT->getElementType()->isStructureType())
St = BindStruct(St, ER, *VI);
else
St = Bind(St, Loc::MakeVal(ER), *VI);
}
return StateMgr.MakeStateWithStore(St, store);
}
const GRState*
RegionStoreManager::BindStruct(const GRState* St, const TypedRegion* R, SVal V){
// FIXME: Verify that we should use getRValueType or getLValueType.
QualType T = R->getRValueType(getContext());
assert(T->isStructureType());
RecordType* RT = cast<RecordType>(T.getTypePtr());
RecordDecl* RD = RT->getDecl();
assert(RD->isDefinition());
nonloc::CompoundVal& CV = cast<nonloc::CompoundVal>(V);
nonloc::CompoundVal::iterator VI = CV.begin(), VE = CV.end();
RecordDecl::field_iterator FI = RD->field_begin(), FE = RD->field_end();
for (; FI != FE; ++FI, ++VI) {
// There may be fewer values than fields only when we are initializing a
// struct decl. In this case, mark the region as having default value.
if (VI == VE) {
// GRStateRef state(St, StateMgr);
//St = state.set<RegionDefaultValue>(R, NonLoc::MakeVal(getBasicVals(), 0,
// false));
break;
}
QualType FTy = (*FI)->getType();
FieldRegion* FR = MRMgr.getFieldRegion(*FI, R);
if (Loc::IsLocType(FTy) || FTy->isIntegerType())
St = Bind(St, Loc::MakeVal(FR), *VI);
else if (FTy->isArrayType())
St = BindArray(St, FR, *VI);
else if (FTy->isStructureType())
St = BindStruct(St, FR, *VI);
}
return St;
}
const GRState* RegionStoreManager::AddRegionView(const GRState* St,
const MemRegion* View,
const MemRegion* Base) {
GRStateRef state(St, StateMgr);
// First, retrieve the region view of the base region.
const RegionViews* d = state.get<RegionViewMap>(Base);
RegionViews L = d ? *d : RVFactory.GetEmptyList();
// Now add View to the region view.
L = RVFactory.Add(View, L);
// Create a new state with the new region view.
return state.set<RegionViewMap>(Base, L);
}
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