forked from OSchip/llvm-project
551 lines
15 KiB
C++
551 lines
15 KiB
C++
//== SymbolManager.h - Management of Symbolic 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 defines SymbolManager, a class that manages symbolic values
|
|
// created for use by ExprEngine and related classes.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
|
|
#include "clang/Analysis/Analyses/LiveVariables.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
|
|
#include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
|
|
using namespace clang;
|
|
using namespace ento;
|
|
|
|
void SymExpr::anchor() { }
|
|
|
|
void SymExpr::dump() const {
|
|
dumpToStream(llvm::errs());
|
|
}
|
|
|
|
void SymIntExpr::dumpToStream(raw_ostream &os) const {
|
|
os << '(';
|
|
getLHS()->dumpToStream(os);
|
|
os << ") "
|
|
<< BinaryOperator::getOpcodeStr(getOpcode()) << ' '
|
|
<< getRHS().getZExtValue();
|
|
if (getRHS().isUnsigned())
|
|
os << 'U';
|
|
}
|
|
|
|
void IntSymExpr::dumpToStream(raw_ostream &os) const {
|
|
os << getLHS().getZExtValue();
|
|
if (getLHS().isUnsigned())
|
|
os << 'U';
|
|
os << ' '
|
|
<< BinaryOperator::getOpcodeStr(getOpcode())
|
|
<< " (";
|
|
getRHS()->dumpToStream(os);
|
|
os << ')';
|
|
}
|
|
|
|
void SymSymExpr::dumpToStream(raw_ostream &os) const {
|
|
os << '(';
|
|
getLHS()->dumpToStream(os);
|
|
os << ") "
|
|
<< BinaryOperator::getOpcodeStr(getOpcode())
|
|
<< " (";
|
|
getRHS()->dumpToStream(os);
|
|
os << ')';
|
|
}
|
|
|
|
void SymbolCast::dumpToStream(raw_ostream &os) const {
|
|
os << '(' << ToTy.getAsString() << ") (";
|
|
Operand->dumpToStream(os);
|
|
os << ')';
|
|
}
|
|
|
|
void SymbolConjured::dumpToStream(raw_ostream &os) const {
|
|
os << "conj_$" << getSymbolID() << '{' << T.getAsString() << '}';
|
|
}
|
|
|
|
void SymbolDerived::dumpToStream(raw_ostream &os) const {
|
|
os << "derived_$" << getSymbolID() << '{'
|
|
<< getParentSymbol() << ',' << getRegion() << '}';
|
|
}
|
|
|
|
void SymbolExtent::dumpToStream(raw_ostream &os) const {
|
|
os << "extent_$" << getSymbolID() << '{' << getRegion() << '}';
|
|
}
|
|
|
|
void SymbolMetadata::dumpToStream(raw_ostream &os) const {
|
|
os << "meta_$" << getSymbolID() << '{'
|
|
<< getRegion() << ',' << T.getAsString() << '}';
|
|
}
|
|
|
|
void SymbolData::anchor() { }
|
|
|
|
void SymbolRegionValue::dumpToStream(raw_ostream &os) const {
|
|
os << "reg_$" << getSymbolID() << "<" << R << ">";
|
|
}
|
|
|
|
bool SymExpr::symbol_iterator::operator==(const symbol_iterator &X) const {
|
|
return itr == X.itr;
|
|
}
|
|
|
|
bool SymExpr::symbol_iterator::operator!=(const symbol_iterator &X) const {
|
|
return itr != X.itr;
|
|
}
|
|
|
|
SymExpr::symbol_iterator::symbol_iterator(const SymExpr *SE) {
|
|
itr.push_back(SE);
|
|
}
|
|
|
|
SymExpr::symbol_iterator &SymExpr::symbol_iterator::operator++() {
|
|
assert(!itr.empty() && "attempting to iterate on an 'end' iterator");
|
|
expand();
|
|
return *this;
|
|
}
|
|
|
|
SymbolRef SymExpr::symbol_iterator::operator*() {
|
|
assert(!itr.empty() && "attempting to dereference an 'end' iterator");
|
|
return itr.back();
|
|
}
|
|
|
|
void SymExpr::symbol_iterator::expand() {
|
|
const SymExpr *SE = itr.pop_back_val();
|
|
|
|
switch (SE->getKind()) {
|
|
case SymExpr::RegionValueKind:
|
|
case SymExpr::ConjuredKind:
|
|
case SymExpr::DerivedKind:
|
|
case SymExpr::ExtentKind:
|
|
case SymExpr::MetadataKind:
|
|
return;
|
|
case SymExpr::CastSymbolKind:
|
|
itr.push_back(cast<SymbolCast>(SE)->getOperand());
|
|
return;
|
|
case SymExpr::SymIntKind:
|
|
itr.push_back(cast<SymIntExpr>(SE)->getLHS());
|
|
return;
|
|
case SymExpr::IntSymKind:
|
|
itr.push_back(cast<IntSymExpr>(SE)->getRHS());
|
|
return;
|
|
case SymExpr::SymSymKind: {
|
|
const SymSymExpr *x = cast<SymSymExpr>(SE);
|
|
itr.push_back(x->getLHS());
|
|
itr.push_back(x->getRHS());
|
|
return;
|
|
}
|
|
}
|
|
llvm_unreachable("unhandled expansion case");
|
|
}
|
|
|
|
unsigned SymExpr::computeComplexity() const {
|
|
unsigned R = 0;
|
|
for (symbol_iterator I = symbol_begin(), E = symbol_end(); I != E; ++I)
|
|
R++;
|
|
return R;
|
|
}
|
|
|
|
const SymbolRegionValue*
|
|
SymbolManager::getRegionValueSymbol(const TypedValueRegion* R) {
|
|
llvm::FoldingSetNodeID profile;
|
|
SymbolRegionValue::Profile(profile, R);
|
|
void *InsertPos;
|
|
SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
|
|
if (!SD) {
|
|
SD = (SymExpr*) BPAlloc.Allocate<SymbolRegionValue>();
|
|
new (SD) SymbolRegionValue(SymbolCounter, R);
|
|
DataSet.InsertNode(SD, InsertPos);
|
|
++SymbolCounter;
|
|
}
|
|
|
|
return cast<SymbolRegionValue>(SD);
|
|
}
|
|
|
|
const SymbolConjured* SymbolManager::conjureSymbol(const Stmt *E,
|
|
const LocationContext *LCtx,
|
|
QualType T,
|
|
unsigned Count,
|
|
const void *SymbolTag) {
|
|
llvm::FoldingSetNodeID profile;
|
|
SymbolConjured::Profile(profile, E, T, Count, LCtx, SymbolTag);
|
|
void *InsertPos;
|
|
SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
|
|
if (!SD) {
|
|
SD = (SymExpr*) BPAlloc.Allocate<SymbolConjured>();
|
|
new (SD) SymbolConjured(SymbolCounter, E, LCtx, T, Count, SymbolTag);
|
|
DataSet.InsertNode(SD, InsertPos);
|
|
++SymbolCounter;
|
|
}
|
|
|
|
return cast<SymbolConjured>(SD);
|
|
}
|
|
|
|
const SymbolDerived*
|
|
SymbolManager::getDerivedSymbol(SymbolRef parentSymbol,
|
|
const TypedValueRegion *R) {
|
|
|
|
llvm::FoldingSetNodeID profile;
|
|
SymbolDerived::Profile(profile, parentSymbol, R);
|
|
void *InsertPos;
|
|
SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
|
|
if (!SD) {
|
|
SD = (SymExpr*) BPAlloc.Allocate<SymbolDerived>();
|
|
new (SD) SymbolDerived(SymbolCounter, parentSymbol, R);
|
|
DataSet.InsertNode(SD, InsertPos);
|
|
++SymbolCounter;
|
|
}
|
|
|
|
return cast<SymbolDerived>(SD);
|
|
}
|
|
|
|
const SymbolExtent*
|
|
SymbolManager::getExtentSymbol(const SubRegion *R) {
|
|
llvm::FoldingSetNodeID profile;
|
|
SymbolExtent::Profile(profile, R);
|
|
void *InsertPos;
|
|
SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
|
|
if (!SD) {
|
|
SD = (SymExpr*) BPAlloc.Allocate<SymbolExtent>();
|
|
new (SD) SymbolExtent(SymbolCounter, R);
|
|
DataSet.InsertNode(SD, InsertPos);
|
|
++SymbolCounter;
|
|
}
|
|
|
|
return cast<SymbolExtent>(SD);
|
|
}
|
|
|
|
const SymbolMetadata*
|
|
SymbolManager::getMetadataSymbol(const MemRegion* R, const Stmt *S, QualType T,
|
|
unsigned Count, const void *SymbolTag) {
|
|
|
|
llvm::FoldingSetNodeID profile;
|
|
SymbolMetadata::Profile(profile, R, S, T, Count, SymbolTag);
|
|
void *InsertPos;
|
|
SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
|
|
if (!SD) {
|
|
SD = (SymExpr*) BPAlloc.Allocate<SymbolMetadata>();
|
|
new (SD) SymbolMetadata(SymbolCounter, R, S, T, Count, SymbolTag);
|
|
DataSet.InsertNode(SD, InsertPos);
|
|
++SymbolCounter;
|
|
}
|
|
|
|
return cast<SymbolMetadata>(SD);
|
|
}
|
|
|
|
const SymbolCast*
|
|
SymbolManager::getCastSymbol(const SymExpr *Op,
|
|
QualType From, QualType To) {
|
|
llvm::FoldingSetNodeID ID;
|
|
SymbolCast::Profile(ID, Op, From, To);
|
|
void *InsertPos;
|
|
SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
|
|
if (!data) {
|
|
data = (SymbolCast*) BPAlloc.Allocate<SymbolCast>();
|
|
new (data) SymbolCast(Op, From, To);
|
|
DataSet.InsertNode(data, InsertPos);
|
|
}
|
|
|
|
return cast<SymbolCast>(data);
|
|
}
|
|
|
|
const SymIntExpr *SymbolManager::getSymIntExpr(const SymExpr *lhs,
|
|
BinaryOperator::Opcode op,
|
|
const llvm::APSInt& v,
|
|
QualType t) {
|
|
llvm::FoldingSetNodeID ID;
|
|
SymIntExpr::Profile(ID, lhs, op, v, t);
|
|
void *InsertPos;
|
|
SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
|
|
|
|
if (!data) {
|
|
data = (SymIntExpr*) BPAlloc.Allocate<SymIntExpr>();
|
|
new (data) SymIntExpr(lhs, op, v, t);
|
|
DataSet.InsertNode(data, InsertPos);
|
|
}
|
|
|
|
return cast<SymIntExpr>(data);
|
|
}
|
|
|
|
const IntSymExpr *SymbolManager::getIntSymExpr(const llvm::APSInt& lhs,
|
|
BinaryOperator::Opcode op,
|
|
const SymExpr *rhs,
|
|
QualType t) {
|
|
llvm::FoldingSetNodeID ID;
|
|
IntSymExpr::Profile(ID, lhs, op, rhs, t);
|
|
void *InsertPos;
|
|
SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
|
|
|
|
if (!data) {
|
|
data = (IntSymExpr*) BPAlloc.Allocate<IntSymExpr>();
|
|
new (data) IntSymExpr(lhs, op, rhs, t);
|
|
DataSet.InsertNode(data, InsertPos);
|
|
}
|
|
|
|
return cast<IntSymExpr>(data);
|
|
}
|
|
|
|
const SymSymExpr *SymbolManager::getSymSymExpr(const SymExpr *lhs,
|
|
BinaryOperator::Opcode op,
|
|
const SymExpr *rhs,
|
|
QualType t) {
|
|
llvm::FoldingSetNodeID ID;
|
|
SymSymExpr::Profile(ID, lhs, op, rhs, t);
|
|
void *InsertPos;
|
|
SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
|
|
|
|
if (!data) {
|
|
data = (SymSymExpr*) BPAlloc.Allocate<SymSymExpr>();
|
|
new (data) SymSymExpr(lhs, op, rhs, t);
|
|
DataSet.InsertNode(data, InsertPos);
|
|
}
|
|
|
|
return cast<SymSymExpr>(data);
|
|
}
|
|
|
|
QualType SymbolConjured::getType() const {
|
|
return T;
|
|
}
|
|
|
|
QualType SymbolDerived::getType() const {
|
|
return R->getValueType();
|
|
}
|
|
|
|
QualType SymbolExtent::getType() const {
|
|
ASTContext &Ctx = R->getMemRegionManager()->getContext();
|
|
return Ctx.getSizeType();
|
|
}
|
|
|
|
QualType SymbolMetadata::getType() const {
|
|
return T;
|
|
}
|
|
|
|
QualType SymbolRegionValue::getType() const {
|
|
return R->getValueType();
|
|
}
|
|
|
|
SymbolManager::~SymbolManager() {
|
|
llvm::DeleteContainerSeconds(SymbolDependencies);
|
|
}
|
|
|
|
bool SymbolManager::canSymbolicate(QualType T) {
|
|
T = T.getCanonicalType();
|
|
|
|
if (Loc::isLocType(T))
|
|
return true;
|
|
|
|
if (T->isIntegralOrEnumerationType())
|
|
return true;
|
|
|
|
if (T->isRecordType() && !T->isUnionType())
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
void SymbolManager::addSymbolDependency(const SymbolRef Primary,
|
|
const SymbolRef Dependent) {
|
|
SymbolDependTy::iterator I = SymbolDependencies.find(Primary);
|
|
SymbolRefSmallVectorTy *dependencies = 0;
|
|
if (I == SymbolDependencies.end()) {
|
|
dependencies = new SymbolRefSmallVectorTy();
|
|
SymbolDependencies[Primary] = dependencies;
|
|
} else {
|
|
dependencies = I->second;
|
|
}
|
|
dependencies->push_back(Dependent);
|
|
}
|
|
|
|
const SymbolRefSmallVectorTy *SymbolManager::getDependentSymbols(
|
|
const SymbolRef Primary) {
|
|
SymbolDependTy::const_iterator I = SymbolDependencies.find(Primary);
|
|
if (I == SymbolDependencies.end())
|
|
return 0;
|
|
return I->second;
|
|
}
|
|
|
|
void SymbolReaper::markDependentsLive(SymbolRef sym) {
|
|
// Do not mark dependents more then once.
|
|
SymbolMapTy::iterator LI = TheLiving.find(sym);
|
|
assert(LI != TheLiving.end() && "The primary symbol is not live.");
|
|
if (LI->second == HaveMarkedDependents)
|
|
return;
|
|
LI->second = HaveMarkedDependents;
|
|
|
|
if (const SymbolRefSmallVectorTy *Deps = SymMgr.getDependentSymbols(sym)) {
|
|
for (SymbolRefSmallVectorTy::const_iterator I = Deps->begin(),
|
|
E = Deps->end(); I != E; ++I) {
|
|
if (TheLiving.find(*I) != TheLiving.end())
|
|
continue;
|
|
markLive(*I);
|
|
}
|
|
}
|
|
}
|
|
|
|
void SymbolReaper::markLive(SymbolRef sym) {
|
|
TheLiving[sym] = NotProcessed;
|
|
TheDead.erase(sym);
|
|
markDependentsLive(sym);
|
|
}
|
|
|
|
void SymbolReaper::markLive(const MemRegion *region) {
|
|
RegionRoots.insert(region);
|
|
}
|
|
|
|
void SymbolReaper::markInUse(SymbolRef sym) {
|
|
if (isa<SymbolMetadata>(sym))
|
|
MetadataInUse.insert(sym);
|
|
}
|
|
|
|
bool SymbolReaper::maybeDead(SymbolRef sym) {
|
|
if (isLive(sym))
|
|
return false;
|
|
|
|
TheDead.insert(sym);
|
|
return true;
|
|
}
|
|
|
|
bool SymbolReaper::isLiveRegion(const MemRegion *MR) {
|
|
if (RegionRoots.count(MR))
|
|
return true;
|
|
|
|
MR = MR->getBaseRegion();
|
|
|
|
if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
|
|
return isLive(SR->getSymbol());
|
|
|
|
if (const VarRegion *VR = dyn_cast<VarRegion>(MR))
|
|
return isLive(VR, true);
|
|
|
|
// FIXME: This is a gross over-approximation. What we really need is a way to
|
|
// tell if anything still refers to this region. Unlike SymbolicRegions,
|
|
// AllocaRegions don't have associated symbols, though, so we don't actually
|
|
// have a way to track their liveness.
|
|
if (isa<AllocaRegion>(MR))
|
|
return true;
|
|
|
|
if (isa<CXXThisRegion>(MR))
|
|
return true;
|
|
|
|
if (isa<MemSpaceRegion>(MR))
|
|
return true;
|
|
|
|
if (isa<CodeTextRegion>(MR))
|
|
return true;
|
|
|
|
return false;
|
|
}
|
|
|
|
bool SymbolReaper::isLive(SymbolRef sym) {
|
|
if (TheLiving.count(sym)) {
|
|
markDependentsLive(sym);
|
|
return true;
|
|
}
|
|
|
|
bool KnownLive;
|
|
|
|
switch (sym->getKind()) {
|
|
case SymExpr::RegionValueKind:
|
|
KnownLive = isLiveRegion(cast<SymbolRegionValue>(sym)->getRegion());
|
|
break;
|
|
case SymExpr::ConjuredKind:
|
|
KnownLive = false;
|
|
break;
|
|
case SymExpr::DerivedKind:
|
|
KnownLive = isLive(cast<SymbolDerived>(sym)->getParentSymbol());
|
|
break;
|
|
case SymExpr::ExtentKind:
|
|
KnownLive = isLiveRegion(cast<SymbolExtent>(sym)->getRegion());
|
|
break;
|
|
case SymExpr::MetadataKind:
|
|
KnownLive = MetadataInUse.count(sym) &&
|
|
isLiveRegion(cast<SymbolMetadata>(sym)->getRegion());
|
|
if (KnownLive)
|
|
MetadataInUse.erase(sym);
|
|
break;
|
|
case SymExpr::SymIntKind:
|
|
KnownLive = isLive(cast<SymIntExpr>(sym)->getLHS());
|
|
break;
|
|
case SymExpr::IntSymKind:
|
|
KnownLive = isLive(cast<IntSymExpr>(sym)->getRHS());
|
|
break;
|
|
case SymExpr::SymSymKind:
|
|
KnownLive = isLive(cast<SymSymExpr>(sym)->getLHS()) &&
|
|
isLive(cast<SymSymExpr>(sym)->getRHS());
|
|
break;
|
|
case SymExpr::CastSymbolKind:
|
|
KnownLive = isLive(cast<SymbolCast>(sym)->getOperand());
|
|
break;
|
|
}
|
|
|
|
if (KnownLive)
|
|
markLive(sym);
|
|
|
|
return KnownLive;
|
|
}
|
|
|
|
bool
|
|
SymbolReaper::isLive(const Stmt *ExprVal, const LocationContext *ELCtx) const {
|
|
if (LCtx == 0)
|
|
return false;
|
|
|
|
if (LCtx != ELCtx) {
|
|
// If the reaper's location context is a parent of the expression's
|
|
// location context, then the expression value is now "out of scope".
|
|
if (LCtx->isParentOf(ELCtx))
|
|
return false;
|
|
return true;
|
|
}
|
|
|
|
// If no statement is provided, everything is this and parent contexts is live.
|
|
if (!Loc)
|
|
return true;
|
|
|
|
return LCtx->getAnalysis<RelaxedLiveVariables>()->isLive(Loc, ExprVal);
|
|
}
|
|
|
|
bool SymbolReaper::isLive(const VarRegion *VR, bool includeStoreBindings) const{
|
|
const StackFrameContext *VarContext = VR->getStackFrame();
|
|
|
|
if (!VarContext)
|
|
return true;
|
|
|
|
if (!LCtx)
|
|
return false;
|
|
const StackFrameContext *CurrentContext = LCtx->getCurrentStackFrame();
|
|
|
|
if (VarContext == CurrentContext) {
|
|
// If no statement is provided, everything is live.
|
|
if (!Loc)
|
|
return true;
|
|
|
|
if (LCtx->getAnalysis<RelaxedLiveVariables>()->isLive(Loc, VR->getDecl()))
|
|
return true;
|
|
|
|
if (!includeStoreBindings)
|
|
return false;
|
|
|
|
unsigned &cachedQuery =
|
|
const_cast<SymbolReaper*>(this)->includedRegionCache[VR];
|
|
|
|
if (cachedQuery) {
|
|
return cachedQuery == 1;
|
|
}
|
|
|
|
// Query the store to see if the region occurs in any live bindings.
|
|
if (Store store = reapedStore.getStore()) {
|
|
bool hasRegion =
|
|
reapedStore.getStoreManager().includedInBindings(store, VR);
|
|
cachedQuery = hasRegion ? 1 : 2;
|
|
return hasRegion;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
return VarContext->isParentOf(CurrentContext);
|
|
}
|
|
|
|
SymbolVisitor::~SymbolVisitor() {}
|