1 //===-- SVals.cpp - Abstract RValues for Path-Sens. Value Tracking --------===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file defines SVal, Loc, and NonLoc, classes that represent
10 // abstract r-values for use with path-sensitive value tracking.
12 //===----------------------------------------------------------------------===//
14 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
15 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/Decl.h"
17 #include "clang/AST/DeclCXX.h"
18 #include "clang/AST/Expr.h"
19 #include "clang/AST/Type.h"
20 #include "clang/Basic/JsonSupport.h"
21 #include "clang/Basic/LLVM.h"
22 #include "clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h"
23 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
24 #include "clang/StaticAnalyzer/Core/PathSensitive/SValBuilder.h"
25 #include "clang/StaticAnalyzer/Core/PathSensitive/SValVisitor.h"
26 #include "clang/StaticAnalyzer/Core/PathSensitive/SymExpr.h"
27 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
28 #include "llvm/ADT/Optional.h"
29 #include "llvm/Support/Casting.h"
30 #include "llvm/Support/Compiler.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/raw_ostream.h"
35 using namespace clang;
38 //===----------------------------------------------------------------------===//
39 // Symbol iteration within an SVal.
40 //===----------------------------------------------------------------------===//
42 //===----------------------------------------------------------------------===//
44 //===----------------------------------------------------------------------===//
46 bool SVal::hasConjuredSymbol() const {
47 if (Optional<nonloc::SymbolVal> SV = getAs<nonloc::SymbolVal>()) {
48 SymbolRef sym = SV->getSymbol();
49 if (isa<SymbolConjured>(sym))
53 if (Optional<loc::MemRegionVal> RV = getAs<loc::MemRegionVal>()) {
54 const MemRegion *R = RV->getRegion();
55 if (const auto *SR = dyn_cast<SymbolicRegion>(R)) {
56 SymbolRef sym = SR->getSymbol();
57 if (isa<SymbolConjured>(sym))
65 const FunctionDecl *SVal::getAsFunctionDecl() const {
66 if (Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>()) {
67 const MemRegion* R = X->getRegion();
68 if (const FunctionCodeRegion *CTR = R->getAs<FunctionCodeRegion>())
69 if (const auto *FD = dyn_cast<FunctionDecl>(CTR->getDecl()))
73 if (auto X = getAs<nonloc::PointerToMember>()) {
74 if (const auto *MD = dyn_cast_or_null<CXXMethodDecl>(X->getDecl()))
80 /// If this SVal is a location (subclasses Loc) and wraps a symbol,
81 /// return that SymbolRef. Otherwise return 0.
83 /// Implicit casts (ex: void* -> char*) can turn Symbolic region into Element
84 /// region. If that is the case, gets the underlining region.
85 /// When IncludeBaseRegions is set to true and the SubRegion is non-symbolic,
86 /// the first symbolic parent region is returned.
87 SymbolRef SVal::getAsLocSymbol(bool IncludeBaseRegions) const {
88 // FIXME: should we consider SymbolRef wrapped in CodeTextRegion?
89 if (const MemRegion *R = getAsRegion())
90 if (const SymbolicRegion *SymR =
91 IncludeBaseRegions ? R->getSymbolicBase()
92 : dyn_cast<SymbolicRegion>(R->StripCasts()))
93 return SymR->getSymbol();
98 /// Get the symbol in the SVal or its base region.
99 SymbolRef SVal::getLocSymbolInBase() const {
100 Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>();
105 const MemRegion *R = X->getRegion();
107 while (const auto *SR = dyn_cast<SubRegion>(R)) {
108 if (const auto *SymR = dyn_cast<SymbolicRegion>(SR))
109 return SymR->getSymbol();
111 R = SR->getSuperRegion();
117 /// If this SVal wraps a symbol return that SymbolRef.
118 /// Otherwise, return 0.
120 /// Casts are ignored during lookup.
121 /// \param IncludeBaseRegions The boolean that controls whether the search
122 /// should continue to the base regions if the region is not symbolic.
123 SymbolRef SVal::getAsSymbol(bool IncludeBaseRegions) const {
124 // FIXME: should we consider SymbolRef wrapped in CodeTextRegion?
125 if (Optional<nonloc::SymbolVal> X = getAs<nonloc::SymbolVal>())
126 return X->getSymbol();
128 return getAsLocSymbol(IncludeBaseRegions);
131 const MemRegion *SVal::getAsRegion() const {
132 if (Optional<loc::MemRegionVal> X = getAs<loc::MemRegionVal>())
133 return X->getRegion();
135 if (Optional<nonloc::LocAsInteger> X = getAs<nonloc::LocAsInteger>())
136 return X->getLoc().getAsRegion();
142 class TypeRetrievingVisitor
143 : public FullSValVisitor<TypeRetrievingVisitor, QualType> {
145 const ASTContext &Context;
148 TypeRetrievingVisitor(const ASTContext &Context) : Context(Context) {}
150 QualType VisitLocMemRegionVal(loc::MemRegionVal MRV) {
151 return Visit(MRV.getRegion());
153 QualType VisitLocGotoLabel(loc::GotoLabel GL) {
154 return QualType{Context.VoidPtrTy};
156 template <class ConcreteInt> QualType VisitConcreteInt(ConcreteInt CI) {
157 const llvm::APSInt &Value = CI.getValue();
158 return Context.getIntTypeForBitwidth(Value.getBitWidth(), Value.isSigned());
160 QualType VisitLocConcreteInt(loc::ConcreteInt CI) {
161 return VisitConcreteInt(CI);
163 QualType VisitNonLocConcreteInt(nonloc::ConcreteInt CI) {
164 return VisitConcreteInt(CI);
166 QualType VisitNonLocLocAsInteger(nonloc::LocAsInteger LI) {
167 QualType NestedType = Visit(LI.getLoc());
168 if (NestedType.isNull())
171 return Context.getIntTypeForBitwidth(LI.getNumBits(),
172 NestedType->isSignedIntegerType());
174 QualType VisitNonLocCompoundVal(nonloc::CompoundVal CV) {
175 return CV.getValue()->getType();
177 QualType VisitNonLocLazyCompoundVal(nonloc::LazyCompoundVal LCV) {
178 return LCV.getRegion()->getValueType();
180 QualType VisitNonLocSymbolVal(nonloc::SymbolVal SV) {
181 return Visit(SV.getSymbol());
183 QualType VisitSymbolicRegion(const SymbolicRegion *SR) {
184 return Visit(SR->getSymbol());
186 QualType VisitTypedRegion(const TypedRegion *TR) {
187 return TR->getLocationType();
189 QualType VisitSymExpr(const SymExpr *SE) { return SE->getType(); }
191 } // end anonymous namespace
193 QualType SVal::getType(const ASTContext &Context) const {
194 TypeRetrievingVisitor TRV{Context};
195 return TRV.Visit(*this);
198 const MemRegion *loc::MemRegionVal::stripCasts(bool StripBaseCasts) const {
199 const MemRegion *R = getRegion();
200 return R ? R->StripCasts(StripBaseCasts) : nullptr;
203 const void *nonloc::LazyCompoundVal::getStore() const {
204 return static_cast<const LazyCompoundValData*>(Data)->getStore();
207 const TypedValueRegion *nonloc::LazyCompoundVal::getRegion() const {
208 return static_cast<const LazyCompoundValData*>(Data)->getRegion();
211 bool nonloc::PointerToMember::isNullMemberPointer() const {
212 return getPTMData().isNull();
215 const NamedDecl *nonloc::PointerToMember::getDecl() const {
216 const auto PTMD = this->getPTMData();
220 const NamedDecl *ND = nullptr;
221 if (PTMD.is<const NamedDecl *>())
222 ND = PTMD.get<const NamedDecl *>();
224 ND = PTMD.get<const PointerToMemberData *>()->getDeclaratorDecl();
229 //===----------------------------------------------------------------------===//
231 //===----------------------------------------------------------------------===//
233 nonloc::CompoundVal::iterator nonloc::CompoundVal::begin() const {
234 return getValue()->begin();
237 nonloc::CompoundVal::iterator nonloc::CompoundVal::end() const {
238 return getValue()->end();
241 nonloc::PointerToMember::iterator nonloc::PointerToMember::begin() const {
242 const PTMDataType PTMD = getPTMData();
243 if (PTMD.is<const NamedDecl *>())
245 return PTMD.get<const PointerToMemberData *>()->begin();
248 nonloc::PointerToMember::iterator nonloc::PointerToMember::end() const {
249 const PTMDataType PTMD = getPTMData();
250 if (PTMD.is<const NamedDecl *>())
252 return PTMD.get<const PointerToMemberData *>()->end();
255 //===----------------------------------------------------------------------===//
256 // Useful predicates.
257 //===----------------------------------------------------------------------===//
259 bool SVal::isConstant() const {
260 return getAs<nonloc::ConcreteInt>() || getAs<loc::ConcreteInt>();
263 bool SVal::isConstant(int I) const {
264 if (Optional<loc::ConcreteInt> LV = getAs<loc::ConcreteInt>())
265 return LV->getValue() == I;
266 if (Optional<nonloc::ConcreteInt> NV = getAs<nonloc::ConcreteInt>())
267 return NV->getValue() == I;
271 bool SVal::isZeroConstant() const {
272 return isConstant(0);
275 //===----------------------------------------------------------------------===//
276 // Transfer function dispatch for Non-Locs.
277 //===----------------------------------------------------------------------===//
279 SVal nonloc::ConcreteInt::evalBinOp(SValBuilder &svalBuilder,
280 BinaryOperator::Opcode Op,
281 const nonloc::ConcreteInt& R) const {
282 const llvm::APSInt* X =
283 svalBuilder.getBasicValueFactory().evalAPSInt(Op, getValue(), R.getValue());
286 return nonloc::ConcreteInt(*X);
288 return UndefinedVal();
292 nonloc::ConcreteInt::evalComplement(SValBuilder &svalBuilder) const {
293 return svalBuilder.makeIntVal(~getValue());
297 nonloc::ConcreteInt::evalMinus(SValBuilder &svalBuilder) const {
298 return svalBuilder.makeIntVal(-getValue());
301 //===----------------------------------------------------------------------===//
302 // Transfer function dispatch for Locs.
303 //===----------------------------------------------------------------------===//
305 SVal loc::ConcreteInt::evalBinOp(BasicValueFactory& BasicVals,
306 BinaryOperator::Opcode Op,
307 const loc::ConcreteInt& R) const {
308 assert(BinaryOperator::isComparisonOp(Op) || Op == BO_Sub);
310 const llvm::APSInt *X = BasicVals.evalAPSInt(Op, getValue(), R.getValue());
313 return nonloc::ConcreteInt(*X);
315 return UndefinedVal();
318 //===----------------------------------------------------------------------===//
320 //===----------------------------------------------------------------------===//
322 LLVM_DUMP_METHOD void SVal::dump() const { dumpToStream(llvm::errs()); }
324 void SVal::printJson(raw_ostream &Out, bool AddQuotes) const {
326 llvm::raw_string_ostream TempOut(Buf);
328 dumpToStream(TempOut);
330 Out << JsonFormat(TempOut.str(), AddQuotes);
333 void SVal::dumpToStream(raw_ostream &os) const {
334 switch (getBaseKind()) {
339 castAs<NonLoc>().dumpToStream(os);
342 castAs<Loc>().dumpToStream(os);
344 case UndefinedValKind:
350 void NonLoc::dumpToStream(raw_ostream &os) const {
351 switch (getSubKind()) {
352 case nonloc::ConcreteIntKind: {
353 const auto &Value = castAs<nonloc::ConcreteInt>().getValue();
354 os << Value << ' ' << (Value.isSigned() ? 'S' : 'U')
355 << Value.getBitWidth() << 'b';
358 case nonloc::SymbolValKind:
359 os << castAs<nonloc::SymbolVal>().getSymbol();
362 case nonloc::LocAsIntegerKind: {
363 const nonloc::LocAsInteger& C = castAs<nonloc::LocAsInteger>();
364 os << C.getLoc() << " [as " << C.getNumBits() << " bit integer]";
367 case nonloc::CompoundValKind: {
368 const nonloc::CompoundVal& C = castAs<nonloc::CompoundVal>();
369 os << "compoundVal{";
371 for (const auto &I : C) {
373 os << ' '; first = false;
383 case nonloc::LazyCompoundValKind: {
384 const nonloc::LazyCompoundVal &C = castAs<nonloc::LazyCompoundVal>();
385 os << "lazyCompoundVal{" << const_cast<void *>(C.getStore())
386 << ',' << C.getRegion()
390 case nonloc::PointerToMemberKind: {
391 os << "pointerToMember{";
392 const nonloc::PointerToMember &CastRes =
393 castAs<nonloc::PointerToMember>();
394 if (CastRes.getDecl())
395 os << "|" << CastRes.getDecl()->getQualifiedNameAsString() << "|";
397 for (const auto &I : CastRes) {
399 os << ' '; first = false;
404 os << (*I).getType().getAsString();
411 assert(false && "Pretty-printed not implemented for this NonLoc.");
416 void Loc::dumpToStream(raw_ostream &os) const {
417 switch (getSubKind()) {
418 case loc::ConcreteIntKind:
419 os << castAs<loc::ConcreteInt>().getValue().getZExtValue() << " (Loc)";
421 case loc::GotoLabelKind:
422 os << "&&" << castAs<loc::GotoLabel>().getLabel()->getName();
424 case loc::MemRegionValKind:
425 os << '&' << castAs<loc::MemRegionVal>().getRegion()->getString();
428 llvm_unreachable("Pretty-printing not implemented for this Loc.");