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

457 lines
13 KiB
C++

//== MemRegion.cpp - Abstract memory regions for static analysis --*- 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 MemRegion and its subclasses. MemRegion defines a
// partially-typed abstraction of memory useful for path-sensitive dataflow
// analyses.
//
//===----------------------------------------------------------------------===//
#include "llvm/Support/raw_ostream.h"
#include "clang/Analysis/PathSensitive/MemRegion.h"
using namespace clang;
MemRegion::~MemRegion() {}
bool SubRegion::isSubRegionOf(const MemRegion* R) const {
const MemRegion* r = getSuperRegion();
while (r != 0) {
if (r == R)
return true;
if (const SubRegion* sr = dyn_cast<SubRegion>(r))
r = sr->getSuperRegion();
else
break;
}
return false;
}
void MemSpaceRegion::Profile(llvm::FoldingSetNodeID& ID) const {
ID.AddInteger((unsigned)getKind());
}
void StringRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
const StringLiteral* Str,
const MemRegion* superRegion) {
ID.AddInteger((unsigned) StringRegionKind);
ID.AddPointer(Str);
ID.AddPointer(superRegion);
}
void AllocaRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
const Expr* Ex, unsigned cnt) {
ID.AddInteger((unsigned) AllocaRegionKind);
ID.AddPointer(Ex);
ID.AddInteger(cnt);
}
void AllocaRegion::Profile(llvm::FoldingSetNodeID& ID) const {
ProfileRegion(ID, Ex, Cnt);
}
void AnonTypedRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, QualType T,
const MemRegion* superRegion) {
ID.AddInteger((unsigned) AnonTypedRegionKind);
ID.Add(T);
ID.AddPointer(superRegion);
}
void CompoundLiteralRegion::Profile(llvm::FoldingSetNodeID& ID) const {
CompoundLiteralRegion::ProfileRegion(ID, CL, superRegion);
}
void CompoundLiteralRegion::ProfileRegion(llvm::FoldingSetNodeID& ID,
const CompoundLiteralExpr* CL,
const MemRegion* superRegion) {
ID.AddInteger((unsigned) CompoundLiteralRegionKind);
ID.AddPointer(CL);
ID.AddPointer(superRegion);
}
void DeclRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, const Decl* D,
const MemRegion* superRegion, Kind k) {
ID.AddInteger((unsigned) k);
ID.AddPointer(D);
ID.AddPointer(superRegion);
}
void DeclRegion::Profile(llvm::FoldingSetNodeID& ID) const {
DeclRegion::ProfileRegion(ID, D, superRegion, getKind());
}
void SymbolicRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, SymbolRef sym) {
ID.AddInteger((unsigned) MemRegion::SymbolicRegionKind);
ID.Add(sym);
}
void SymbolicRegion::Profile(llvm::FoldingSetNodeID& ID) const {
SymbolicRegion::ProfileRegion(ID, sym);
}
void ElementRegion::ProfileRegion(llvm::FoldingSetNodeID& ID, SVal Idx,
const MemRegion* superRegion) {
ID.AddInteger(MemRegion::ElementRegionKind);
ID.AddPointer(superRegion);
Idx.Profile(ID);
}
void ElementRegion::Profile(llvm::FoldingSetNodeID& ID) const {
ElementRegion::ProfileRegion(ID, Index, superRegion);
}
//===----------------------------------------------------------------------===//
// getLValueType() and getRValueType()
//===----------------------------------------------------------------------===//
QualType SymbolicRegion::getRValueType(ASTContext& C) const {
const SymbolData& data = SymMgr.getSymbolData(sym);
// Get the type of the symbol.
QualType T = data.getType(C);
// Only when the symbol has pointer type it can have a symbolic region
// associated with it.
PointerType* PTy = cast<PointerType>(T.getTypePtr()->getDesugaredType());
// The type of the symbolic region is the pointee type of the symbol.
return PTy->getPointeeType();
}
QualType ElementRegion::getRValueType(ASTContext& C) const {
// Strip off typedefs from the ArrayRegion's RvalueType.
QualType T = getArrayRegion()->getRValueType(C)->getDesugaredType();
if (ArrayType* AT = dyn_cast<ArrayType>(T.getTypePtr()))
return AT->getElementType();
// If the RValueType of the array region isn't an ArrayType, then essentially
// the element's
return T;
}
QualType StringRegion::getRValueType(ASTContext& C) const {
return Str->getType();
}
//===----------------------------------------------------------------------===//
// Region pretty-printing.
//===----------------------------------------------------------------------===//
std::string MemRegion::getString() const {
std::string s;
llvm::raw_string_ostream os(s);
print(os);
return os.str();
}
void MemRegion::print(llvm::raw_ostream& os) const {
os << "<Unknown Region>";
}
void AllocaRegion::print(llvm::raw_ostream& os) const {
os << "alloca{" << (void*) Ex << ',' << Cnt << '}';
}
void AnonTypedRegion::print(llvm::raw_ostream& os) const {
os << "anon_type{" << T.getAsString() << ',';
getSuperRegion()->print(os);
os << '}';
}
void VarRegion::print(llvm::raw_ostream& os) const {
os << cast<VarDecl>(D)->getNameAsString();
}
void SymbolicRegion::print(llvm::raw_ostream& os) const {
os << "SymRegion-";
sym.print(os);
}
void FieldRegion::print(llvm::raw_ostream& os) const {
superRegion->print(os);
os << "->" << getDecl()->getNameAsString();
}
void ElementRegion::print(llvm::raw_ostream& os) const {
superRegion->print(os);
os << '['; Index.print(os); os << ']';
}
void CompoundLiteralRegion::print(llvm::raw_ostream& os) const {
// FIXME: More elaborate pretty-printing.
os << "{ " << (void*) CL << " }";
}
void StringRegion::print(llvm::raw_ostream& os) const {
Str->printPretty(os);
}
//===----------------------------------------------------------------------===//
// MemRegionManager methods.
//===----------------------------------------------------------------------===//
MemSpaceRegion* MemRegionManager::LazyAllocate(MemSpaceRegion*& region) {
if (!region) {
region = (MemSpaceRegion*) A.Allocate<MemSpaceRegion>();
new (region) MemSpaceRegion();
}
return region;
}
MemSpaceRegion* MemRegionManager::getStackRegion() {
return LazyAllocate(stack);
}
MemSpaceRegion* MemRegionManager::getGlobalsRegion() {
return LazyAllocate(globals);
}
MemSpaceRegion* MemRegionManager::getHeapRegion() {
return LazyAllocate(heap);
}
MemSpaceRegion* MemRegionManager::getUnknownRegion() {
return LazyAllocate(unknown);
}
bool MemRegionManager::onStack(const MemRegion* R) {
while (const SubRegion* SR = dyn_cast<SubRegion>(R))
R = SR->getSuperRegion();
return (R != 0) && (R == stack);
}
bool MemRegionManager::onHeap(const MemRegion* R) {
while (const SubRegion* SR = dyn_cast<SubRegion>(R))
R = SR->getSuperRegion();
return (R != 0) && (R == heap);
}
StringRegion* MemRegionManager::getStringRegion(const StringLiteral* Str) {
llvm::FoldingSetNodeID ID;
MemSpaceRegion* GlobalsR = getGlobalsRegion();
StringRegion::ProfileRegion(ID, Str, GlobalsR);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
StringRegion* R = cast_or_null<StringRegion>(data);
if (!R) {
R = (StringRegion*) A.Allocate<StringRegion>();
new (R) StringRegion(Str, GlobalsR);
Regions.InsertNode(R, InsertPos);
}
return R;
}
VarRegion* MemRegionManager::getVarRegion(const VarDecl* d) {
const MemRegion* superRegion = d->hasLocalStorage() ? getStackRegion()
: getGlobalsRegion();
llvm::FoldingSetNodeID ID;
DeclRegion::ProfileRegion(ID, d, superRegion, MemRegion::VarRegionKind);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
VarRegion* R = cast_or_null<VarRegion>(data);
if (!R) {
R = (VarRegion*) A.Allocate<VarRegion>();
new (R) VarRegion(d, superRegion);
Regions.InsertNode(R, InsertPos);
}
return R;
}
CompoundLiteralRegion*
MemRegionManager::getCompoundLiteralRegion(const CompoundLiteralExpr* CL) {
// Is this compound literal allocated on the stack or is part of the
// global constant pool?
const MemRegion* superRegion = CL->isFileScope() ?
getGlobalsRegion() : getStackRegion();
// Profile the compound literal.
llvm::FoldingSetNodeID ID;
CompoundLiteralRegion::ProfileRegion(ID, CL, superRegion);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
CompoundLiteralRegion* R = cast_or_null<CompoundLiteralRegion>(data);
if (!R) {
R = (CompoundLiteralRegion*) A.Allocate<CompoundLiteralRegion>();
new (R) CompoundLiteralRegion(CL, superRegion);
Regions.InsertNode(R, InsertPos);
}
return R;
}
ElementRegion*
MemRegionManager::getElementRegion(SVal Idx, const TypedRegion* superRegion){
llvm::FoldingSetNodeID ID;
ElementRegion::ProfileRegion(ID, Idx, superRegion);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
ElementRegion* R = cast_or_null<ElementRegion>(data);
if (!R) {
R = (ElementRegion*) A.Allocate<ElementRegion>();
new (R) ElementRegion(Idx, superRegion);
Regions.InsertNode(R, InsertPos);
}
return R;
}
/// getSymbolicRegion - Retrieve or create a "symbolic" memory region.
SymbolicRegion* MemRegionManager::getSymbolicRegion(const SymbolRef sym,
const SymbolManager& mgr) {
llvm::FoldingSetNodeID ID;
SymbolicRegion::ProfileRegion(ID, sym);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
SymbolicRegion* R = cast_or_null<SymbolicRegion>(data);
if (!R) {
R = (SymbolicRegion*) A.Allocate<SymbolicRegion>();
// SymbolicRegion's storage class is usually unknown.
new (R) SymbolicRegion(sym, mgr, getUnknownRegion());
Regions.InsertNode(R, InsertPos);
}
return R;
}
FieldRegion* MemRegionManager::getFieldRegion(const FieldDecl* d,
const MemRegion* superRegion) {
llvm::FoldingSetNodeID ID;
DeclRegion::ProfileRegion(ID, d, superRegion, MemRegion::FieldRegionKind);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
FieldRegion* R = cast_or_null<FieldRegion>(data);
if (!R) {
R = (FieldRegion*) A.Allocate<FieldRegion>();
new (R) FieldRegion(d, superRegion);
Regions.InsertNode(R, InsertPos);
}
return R;
}
ObjCIvarRegion*
MemRegionManager::getObjCIvarRegion(const ObjCIvarDecl* d,
const MemRegion* superRegion) {
llvm::FoldingSetNodeID ID;
DeclRegion::ProfileRegion(ID, d, superRegion, MemRegion::ObjCIvarRegionKind);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
ObjCIvarRegion* R = cast_or_null<ObjCIvarRegion>(data);
if (!R) {
R = (ObjCIvarRegion*) A.Allocate<ObjCIvarRegion>();
new (R) ObjCIvarRegion(d, superRegion);
Regions.InsertNode(R, InsertPos);
}
return R;
}
ObjCObjectRegion*
MemRegionManager::getObjCObjectRegion(const ObjCInterfaceDecl* d,
const MemRegion* superRegion) {
llvm::FoldingSetNodeID ID;
DeclRegion::ProfileRegion(ID, d, superRegion,
MemRegion::ObjCObjectRegionKind);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
ObjCObjectRegion* R = cast_or_null<ObjCObjectRegion>(data);
if (!R) {
R = (ObjCObjectRegion*) A.Allocate<ObjCObjectRegion>();
new (R) ObjCObjectRegion(d, superRegion);
Regions.InsertNode(R, InsertPos);
}
return R;
}
AnonTypedRegion*
MemRegionManager::getAnonTypedRegion(QualType t, const MemRegion* superRegion) {
llvm::FoldingSetNodeID ID;
AnonTypedRegion::ProfileRegion(ID, t, superRegion);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
AnonTypedRegion* R = cast_or_null<AnonTypedRegion>(data);
if (!R) {
R = (AnonTypedRegion*) A.Allocate<AnonTypedRegion>();
new (R) AnonTypedRegion(t, superRegion);
Regions.InsertNode(R, InsertPos);
}
return R;
}
AllocaRegion* MemRegionManager::getAllocaRegion(const Expr* E, unsigned cnt) {
llvm::FoldingSetNodeID ID;
AllocaRegion::ProfileRegion(ID, E, cnt);
void* InsertPos;
MemRegion* data = Regions.FindNodeOrInsertPos(ID, InsertPos);
AllocaRegion* R = cast_or_null<AllocaRegion>(data);
if (!R) {
R = (AllocaRegion*) A.Allocate<AllocaRegion>();
new (R) AllocaRegion(E, cnt, getStackRegion());
Regions.InsertNode(R, InsertPos);
}
return R;
}
bool MemRegionManager::hasStackStorage(const MemRegion* R) {
// Only subregions can have stack storage.
const SubRegion* SR = dyn_cast<SubRegion>(R);
if (!SR)
return false;
MemSpaceRegion* S = getStackRegion();
while (SR) {
R = SR->getSuperRegion();
if (R == S)
return true;
SR = dyn_cast<SubRegion>(R);
}
return false;
}