1 //== SymbolManager.h - Management of Symbolic Values ------------*- C++ -*--==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines SymbolManager, a class that manages symbolic values
11 // created for use by ExprEngine and related classes.
13 //===----------------------------------------------------------------------===//
15 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
16 #include "clang/Analysis/Analyses/LiveVariables.h"
17 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
18 #include "clang/StaticAnalyzer/Core/PathSensitive/Store.h"
19 #include "llvm/Support/raw_ostream.h"
21 using namespace clang;
24 void SymExpr::anchor() { }
26 void SymExpr::dump() const {
27 dumpToStream(llvm::errs());
30 void SymIntExpr::dumpToStream(raw_ostream &os) const {
32 getLHS()->dumpToStream(os);
34 << BinaryOperator::getOpcodeStr(getOpcode()) << ' '
35 << getRHS().getZExtValue();
36 if (getRHS().isUnsigned())
40 void IntSymExpr::dumpToStream(raw_ostream &os) const {
41 os << getLHS().getZExtValue();
42 if (getLHS().isUnsigned())
45 << BinaryOperator::getOpcodeStr(getOpcode())
47 getRHS()->dumpToStream(os);
51 void SymSymExpr::dumpToStream(raw_ostream &os) const {
53 getLHS()->dumpToStream(os);
55 << BinaryOperator::getOpcodeStr(getOpcode())
57 getRHS()->dumpToStream(os);
61 void SymbolCast::dumpToStream(raw_ostream &os) const {
62 os << '(' << ToTy.getAsString() << ") (";
63 Operand->dumpToStream(os);
67 void SymbolConjured::dumpToStream(raw_ostream &os) const {
68 os << "conj_$" << getSymbolID() << '{' << T.getAsString() << '}';
71 void SymbolDerived::dumpToStream(raw_ostream &os) const {
72 os << "derived_$" << getSymbolID() << '{'
73 << getParentSymbol() << ',' << getRegion() << '}';
76 void SymbolExtent::dumpToStream(raw_ostream &os) const {
77 os << "extent_$" << getSymbolID() << '{' << getRegion() << '}';
80 void SymbolMetadata::dumpToStream(raw_ostream &os) const {
81 os << "meta_$" << getSymbolID() << '{'
82 << getRegion() << ',' << T.getAsString() << '}';
85 void SymbolData::anchor() { }
87 void SymbolRegionValue::dumpToStream(raw_ostream &os) const {
88 os << "reg_$" << getSymbolID() << "<" << R << ">";
91 bool SymExpr::symbol_iterator::operator==(const symbol_iterator &X) const {
95 bool SymExpr::symbol_iterator::operator!=(const symbol_iterator &X) const {
99 SymExpr::symbol_iterator::symbol_iterator(const SymExpr *SE) {
103 SymExpr::symbol_iterator &SymExpr::symbol_iterator::operator++() {
104 assert(!itr.empty() && "attempting to iterate on an 'end' iterator");
109 SymbolRef SymExpr::symbol_iterator::operator*() {
110 assert(!itr.empty() && "attempting to dereference an 'end' iterator");
114 void SymExpr::symbol_iterator::expand() {
115 const SymExpr *SE = itr.back();
118 switch (SE->getKind()) {
119 case SymExpr::RegionValueKind:
120 case SymExpr::ConjuredKind:
121 case SymExpr::DerivedKind:
122 case SymExpr::ExtentKind:
123 case SymExpr::MetadataKind:
125 case SymExpr::CastSymbolKind:
126 itr.push_back(cast<SymbolCast>(SE)->getOperand());
128 case SymExpr::SymIntKind:
129 itr.push_back(cast<SymIntExpr>(SE)->getLHS());
131 case SymExpr::IntSymKind:
132 itr.push_back(cast<IntSymExpr>(SE)->getRHS());
134 case SymExpr::SymSymKind: {
135 const SymSymExpr *x = cast<SymSymExpr>(SE);
136 itr.push_back(x->getLHS());
137 itr.push_back(x->getRHS());
141 llvm_unreachable("unhandled expansion case");
144 unsigned SymExpr::computeComplexity() const {
146 for (symbol_iterator I = symbol_begin(), E = symbol_end(); I != E; ++I)
151 const SymbolRegionValue*
152 SymbolManager::getRegionValueSymbol(const TypedValueRegion* R) {
153 llvm::FoldingSetNodeID profile;
154 SymbolRegionValue::Profile(profile, R);
156 SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
158 SD = (SymExpr*) BPAlloc.Allocate<SymbolRegionValue>();
159 new (SD) SymbolRegionValue(SymbolCounter, R);
160 DataSet.InsertNode(SD, InsertPos);
164 return cast<SymbolRegionValue>(SD);
167 const SymbolConjured* SymbolManager::conjureSymbol(const Stmt *E,
168 const LocationContext *LCtx,
171 const void *SymbolTag) {
172 llvm::FoldingSetNodeID profile;
173 SymbolConjured::Profile(profile, E, T, Count, LCtx, SymbolTag);
175 SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
177 SD = (SymExpr*) BPAlloc.Allocate<SymbolConjured>();
178 new (SD) SymbolConjured(SymbolCounter, E, LCtx, T, Count, SymbolTag);
179 DataSet.InsertNode(SD, InsertPos);
183 return cast<SymbolConjured>(SD);
187 SymbolManager::getDerivedSymbol(SymbolRef parentSymbol,
188 const TypedValueRegion *R) {
190 llvm::FoldingSetNodeID profile;
191 SymbolDerived::Profile(profile, parentSymbol, R);
193 SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
195 SD = (SymExpr*) BPAlloc.Allocate<SymbolDerived>();
196 new (SD) SymbolDerived(SymbolCounter, parentSymbol, R);
197 DataSet.InsertNode(SD, InsertPos);
201 return cast<SymbolDerived>(SD);
205 SymbolManager::getExtentSymbol(const SubRegion *R) {
206 llvm::FoldingSetNodeID profile;
207 SymbolExtent::Profile(profile, R);
209 SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
211 SD = (SymExpr*) BPAlloc.Allocate<SymbolExtent>();
212 new (SD) SymbolExtent(SymbolCounter, R);
213 DataSet.InsertNode(SD, InsertPos);
217 return cast<SymbolExtent>(SD);
220 const SymbolMetadata*
221 SymbolManager::getMetadataSymbol(const MemRegion* R, const Stmt *S, QualType T,
222 unsigned Count, const void *SymbolTag) {
224 llvm::FoldingSetNodeID profile;
225 SymbolMetadata::Profile(profile, R, S, T, Count, SymbolTag);
227 SymExpr *SD = DataSet.FindNodeOrInsertPos(profile, InsertPos);
229 SD = (SymExpr*) BPAlloc.Allocate<SymbolMetadata>();
230 new (SD) SymbolMetadata(SymbolCounter, R, S, T, Count, SymbolTag);
231 DataSet.InsertNode(SD, InsertPos);
235 return cast<SymbolMetadata>(SD);
239 SymbolManager::getCastSymbol(const SymExpr *Op,
240 QualType From, QualType To) {
241 llvm::FoldingSetNodeID ID;
242 SymbolCast::Profile(ID, Op, From, To);
244 SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
246 data = (SymbolCast*) BPAlloc.Allocate<SymbolCast>();
247 new (data) SymbolCast(Op, From, To);
248 DataSet.InsertNode(data, InsertPos);
251 return cast<SymbolCast>(data);
254 const SymIntExpr *SymbolManager::getSymIntExpr(const SymExpr *lhs,
255 BinaryOperator::Opcode op,
256 const llvm::APSInt& v,
258 llvm::FoldingSetNodeID ID;
259 SymIntExpr::Profile(ID, lhs, op, v, t);
261 SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
264 data = (SymIntExpr*) BPAlloc.Allocate<SymIntExpr>();
265 new (data) SymIntExpr(lhs, op, v, t);
266 DataSet.InsertNode(data, InsertPos);
269 return cast<SymIntExpr>(data);
272 const IntSymExpr *SymbolManager::getIntSymExpr(const llvm::APSInt& lhs,
273 BinaryOperator::Opcode op,
276 llvm::FoldingSetNodeID ID;
277 IntSymExpr::Profile(ID, lhs, op, rhs, t);
279 SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
282 data = (IntSymExpr*) BPAlloc.Allocate<IntSymExpr>();
283 new (data) IntSymExpr(lhs, op, rhs, t);
284 DataSet.InsertNode(data, InsertPos);
287 return cast<IntSymExpr>(data);
290 const SymSymExpr *SymbolManager::getSymSymExpr(const SymExpr *lhs,
291 BinaryOperator::Opcode op,
294 llvm::FoldingSetNodeID ID;
295 SymSymExpr::Profile(ID, lhs, op, rhs, t);
297 SymExpr *data = DataSet.FindNodeOrInsertPos(ID, InsertPos);
300 data = (SymSymExpr*) BPAlloc.Allocate<SymSymExpr>();
301 new (data) SymSymExpr(lhs, op, rhs, t);
302 DataSet.InsertNode(data, InsertPos);
305 return cast<SymSymExpr>(data);
308 QualType SymbolConjured::getType() const {
312 QualType SymbolDerived::getType() const {
313 return R->getValueType();
316 QualType SymbolExtent::getType() const {
317 ASTContext &Ctx = R->getMemRegionManager()->getContext();
318 return Ctx.getSizeType();
321 QualType SymbolMetadata::getType() const {
325 QualType SymbolRegionValue::getType() const {
326 return R->getValueType();
329 SymbolManager::~SymbolManager() {
330 for (SymbolDependTy::const_iterator I = SymbolDependencies.begin(),
331 E = SymbolDependencies.end(); I != E; ++I) {
337 bool SymbolManager::canSymbolicate(QualType T) {
338 T = T.getCanonicalType();
340 if (Loc::isLocType(T))
343 if (T->isIntegralOrEnumerationType())
346 if (T->isRecordType() && !T->isUnionType())
352 void SymbolManager::addSymbolDependency(const SymbolRef Primary,
353 const SymbolRef Dependent) {
354 SymbolDependTy::iterator I = SymbolDependencies.find(Primary);
355 SymbolRefSmallVectorTy *dependencies = 0;
356 if (I == SymbolDependencies.end()) {
357 dependencies = new SymbolRefSmallVectorTy();
358 SymbolDependencies[Primary] = dependencies;
360 dependencies = I->second;
362 dependencies->push_back(Dependent);
365 const SymbolRefSmallVectorTy *SymbolManager::getDependentSymbols(
366 const SymbolRef Primary) {
367 SymbolDependTy::const_iterator I = SymbolDependencies.find(Primary);
368 if (I == SymbolDependencies.end())
373 void SymbolReaper::markDependentsLive(SymbolRef sym) {
374 // Do not mark dependents more then once.
375 SymbolMapTy::iterator LI = TheLiving.find(sym);
376 assert(LI != TheLiving.end() && "The primary symbol is not live.");
377 if (LI->second == HaveMarkedDependents)
379 LI->second = HaveMarkedDependents;
381 if (const SymbolRefSmallVectorTy *Deps = SymMgr.getDependentSymbols(sym)) {
382 for (SymbolRefSmallVectorTy::const_iterator I = Deps->begin(),
383 E = Deps->end(); I != E; ++I) {
384 if (TheLiving.find(*I) != TheLiving.end())
391 void SymbolReaper::markLive(SymbolRef sym) {
392 TheLiving[sym] = NotProcessed;
394 markDependentsLive(sym);
397 void SymbolReaper::markLive(const MemRegion *region) {
398 RegionRoots.insert(region);
401 void SymbolReaper::markInUse(SymbolRef sym) {
402 if (isa<SymbolMetadata>(sym))
403 MetadataInUse.insert(sym);
406 bool SymbolReaper::maybeDead(SymbolRef sym) {
414 bool SymbolReaper::isLiveRegion(const MemRegion *MR) {
415 if (RegionRoots.count(MR))
418 MR = MR->getBaseRegion();
420 if (const SymbolicRegion *SR = dyn_cast<SymbolicRegion>(MR))
421 return isLive(SR->getSymbol());
423 if (const VarRegion *VR = dyn_cast<VarRegion>(MR))
424 return isLive(VR, true);
426 // FIXME: This is a gross over-approximation. What we really need is a way to
427 // tell if anything still refers to this region. Unlike SymbolicRegions,
428 // AllocaRegions don't have associated symbols, though, so we don't actually
429 // have a way to track their liveness.
430 if (isa<AllocaRegion>(MR))
433 if (isa<CXXThisRegion>(MR))
436 if (isa<MemSpaceRegion>(MR))
442 bool SymbolReaper::isLive(SymbolRef sym) {
443 if (TheLiving.count(sym)) {
444 markDependentsLive(sym);
450 switch (sym->getKind()) {
451 case SymExpr::RegionValueKind:
452 KnownLive = isLiveRegion(cast<SymbolRegionValue>(sym)->getRegion());
454 case SymExpr::ConjuredKind:
457 case SymExpr::DerivedKind:
458 KnownLive = isLive(cast<SymbolDerived>(sym)->getParentSymbol());
460 case SymExpr::ExtentKind:
461 KnownLive = isLiveRegion(cast<SymbolExtent>(sym)->getRegion());
463 case SymExpr::MetadataKind:
464 KnownLive = MetadataInUse.count(sym) &&
465 isLiveRegion(cast<SymbolMetadata>(sym)->getRegion());
467 MetadataInUse.erase(sym);
469 case SymExpr::SymIntKind:
470 KnownLive = isLive(cast<SymIntExpr>(sym)->getLHS());
472 case SymExpr::IntSymKind:
473 KnownLive = isLive(cast<IntSymExpr>(sym)->getRHS());
475 case SymExpr::SymSymKind:
476 KnownLive = isLive(cast<SymSymExpr>(sym)->getLHS()) &&
477 isLive(cast<SymSymExpr>(sym)->getRHS());
479 case SymExpr::CastSymbolKind:
480 KnownLive = isLive(cast<SymbolCast>(sym)->getOperand());
491 SymbolReaper::isLive(const Stmt *ExprVal, const LocationContext *ELCtx) const {
496 // If the reaper's location context is a parent of the expression's
497 // location context, then the expression value is now "out of scope".
498 if (LCtx->isParentOf(ELCtx))
503 // If no statement is provided, everything is this and parent contexts is live.
507 return LCtx->getAnalysis<RelaxedLiveVariables>()->isLive(Loc, ExprVal);
510 bool SymbolReaper::isLive(const VarRegion *VR, bool includeStoreBindings) const{
511 const StackFrameContext *VarContext = VR->getStackFrame();
518 const StackFrameContext *CurrentContext = LCtx->getCurrentStackFrame();
520 if (VarContext == CurrentContext) {
521 // If no statement is provided, everything is live.
525 if (LCtx->getAnalysis<RelaxedLiveVariables>()->isLive(Loc, VR->getDecl()))
528 if (!includeStoreBindings)
531 unsigned &cachedQuery =
532 const_cast<SymbolReaper*>(this)->includedRegionCache[VR];
535 return cachedQuery == 1;
538 // Query the store to see if the region occurs in any live bindings.
539 if (Store store = reapedStore.getStore()) {
541 reapedStore.getStoreManager().includedInBindings(store, VR);
542 cachedQuery = hasRegion ? 1 : 2;
549 return VarContext->isParentOf(CurrentContext);
552 SymbolVisitor::~SymbolVisitor() {}