1 //== SVals.h - Abstract Values for Static Analysis ---------*- 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 SVal, Loc, and NonLoc, classes that represent
11 // abstract r-values for use with path-sensitive value tracking.
13 //===----------------------------------------------------------------------===//
15 #ifndef LLVM_CLANG_GR_RVALUE_H
16 #define LLVM_CLANG_GR_RVALUE_H
18 #include "clang/Basic/LLVM.h"
19 #include "clang/StaticAnalyzer/Core/PathSensitive/ProgramState_Fwd.h"
20 #include "clang/StaticAnalyzer/Core/PathSensitive/SymbolManager.h"
21 #include "llvm/ADT/ImmutableList.h"
23 //==------------------------------------------------------------------------==//
25 //==------------------------------------------------------------------------==//
31 class CompoundValData;
32 class LazyCompoundValData;
34 class BasicValueFactory;
36 class TypedValueRegion;
37 class MemRegionManager;
38 class ProgramStateManager;
41 /// SVal - This represents a symbolic expression, which can be either
42 /// an L-value or an R-value.
47 // The enumerators must be representable using 2 bits.
48 UndefinedKind = 0, // for subclass UndefinedVal (an uninitialized value)
49 UnknownKind = 1, // for subclass UnknownVal (a void value)
50 LocKind = 2, // for subclass Loc (an L-value)
51 NonLocKind = 3 // for subclass NonLoc (an R-value that's not
54 enum { BaseBits = 2, BaseMask = 0x3 };
59 /// The lowest 2 bits are a BaseKind (0 -- 3).
60 /// The higher bits are an unsigned "kind" value.
63 explicit SVal(const void *d, bool isLoc, unsigned ValKind)
64 : Data(d), Kind((isLoc ? LocKind : NonLocKind) | (ValKind << BaseBits)) {}
66 explicit SVal(BaseKind k, const void *D = NULL)
70 explicit SVal() : Data(0), Kind(0) {}
72 /// \brief Convert to the specified SVal type, asserting that this SVal is of
76 assert(T::isKind(*this));
83 /// \brief Convert to the specified SVal type, returning None if this SVal is
84 /// not of the desired type.
86 Optional<T> getAs() const {
87 if (!T::isKind(*this))
95 /// BufferTy - A temporary buffer to hold a set of SVals.
96 typedef SmallVector<SVal,5> BufferTy;
98 inline unsigned getRawKind() const { return Kind; }
99 inline BaseKind getBaseKind() const { return (BaseKind) (Kind & BaseMask); }
100 inline unsigned getSubKind() const { return (Kind & ~BaseMask) >> BaseBits; }
102 // This method is required for using SVal in a FoldingSetNode. It
103 // extracts a unique signature for this SVal object.
104 inline void Profile(llvm::FoldingSetNodeID& ID) const {
105 ID.AddInteger((unsigned) getRawKind());
109 inline bool operator==(const SVal& R) const {
110 return getRawKind() == R.getRawKind() && Data == R.Data;
113 inline bool operator!=(const SVal& R) const {
114 return !(*this == R);
117 inline bool isUnknown() const {
118 return getRawKind() == UnknownKind;
121 inline bool isUndef() const {
122 return getRawKind() == UndefinedKind;
125 inline bool isUnknownOrUndef() const {
126 return getRawKind() <= UnknownKind;
129 inline bool isValid() const {
130 return getRawKind() > UnknownKind;
133 bool isConstant() const;
135 bool isConstant(int I) const;
137 bool isZeroConstant() const;
139 /// hasConjuredSymbol - If this SVal wraps a conjured symbol, return true;
140 bool hasConjuredSymbol() const;
142 /// getAsFunctionDecl - If this SVal is a MemRegionVal and wraps a
143 /// CodeTextRegion wrapping a FunctionDecl, return that FunctionDecl.
144 /// Otherwise return 0.
145 const FunctionDecl *getAsFunctionDecl() const;
147 /// \brief If this SVal is a location and wraps a symbol, return that
148 /// SymbolRef. Otherwise return 0.
150 /// Casts are ignored during lookup.
151 /// \param IncludeBaseRegions The boolean that controls whether the search
152 /// should continue to the base regions if the region is not symbolic.
153 SymbolRef getAsLocSymbol(bool IncludeBaseRegions = false) const;
155 /// Get the symbol in the SVal or its base region.
156 SymbolRef getLocSymbolInBase() const;
158 /// \brief If this SVal wraps a symbol return that SymbolRef.
159 /// Otherwise, return 0.
161 /// Casts are ignored during lookup.
162 /// \param IncludeBaseRegions The boolean that controls whether the search
163 /// should continue to the base regions if the region is not symbolic.
164 SymbolRef getAsSymbol(bool IncludeBaseRegions = false) const;
166 /// getAsSymbolicExpression - If this Sval wraps a symbolic expression then
167 /// return that expression. Otherwise return NULL.
168 const SymExpr *getAsSymbolicExpression() const;
170 const SymExpr* getAsSymExpr() const;
172 const MemRegion *getAsRegion() const;
174 void dumpToStream(raw_ostream &OS) const;
177 SymExpr::symbol_iterator symbol_begin() const {
178 const SymExpr *SE = getAsSymbolicExpression();
180 return SE->symbol_begin();
182 return SymExpr::symbol_iterator();
185 SymExpr::symbol_iterator symbol_end() const {
186 return SymExpr::symbol_end();
191 class UndefinedVal : public SVal {
193 UndefinedVal() : SVal(UndefinedKind) {}
197 static bool isKind(const SVal& V) {
198 return V.getBaseKind() == UndefinedKind;
202 class DefinedOrUnknownSVal : public SVal {
204 // We want calling these methods to be a compiler error since they are
205 // tautologically false.
206 bool isUndef() const LLVM_DELETED_FUNCTION;
207 bool isValid() const LLVM_DELETED_FUNCTION;
210 DefinedOrUnknownSVal() {}
211 explicit DefinedOrUnknownSVal(const void *d, bool isLoc, unsigned ValKind)
212 : SVal(d, isLoc, ValKind) {}
214 explicit DefinedOrUnknownSVal(BaseKind k, void *D = NULL)
219 static bool isKind(const SVal& V) {
224 class UnknownVal : public DefinedOrUnknownSVal {
226 explicit UnknownVal() : DefinedOrUnknownSVal(UnknownKind) {}
230 static bool isKind(const SVal &V) {
231 return V.getBaseKind() == UnknownKind;
235 class DefinedSVal : public DefinedOrUnknownSVal {
237 // We want calling these methods to be a compiler error since they are
238 // tautologically true/false.
239 bool isUnknown() const LLVM_DELETED_FUNCTION;
240 bool isUnknownOrUndef() const LLVM_DELETED_FUNCTION;
241 bool isValid() const LLVM_DELETED_FUNCTION;
244 explicit DefinedSVal(const void *d, bool isLoc, unsigned ValKind)
245 : DefinedOrUnknownSVal(d, isLoc, ValKind) {}
248 static bool isKind(const SVal& V) {
249 return !V.isUnknownOrUndef();
254 /// \brief Represents an SVal that is guaranteed to not be UnknownVal.
255 class KnownSVal : public SVal {
258 static bool isKind(const SVal &V) {
259 return !V.isUnknown();
262 KnownSVal(const DefinedSVal &V) : SVal(V) {}
263 KnownSVal(const UndefinedVal &V) : SVal(V) {}
266 class NonLoc : public DefinedSVal {
269 explicit NonLoc(unsigned SubKind, const void *d)
270 : DefinedSVal(d, false, SubKind) {}
273 void dumpToStream(raw_ostream &Out) const;
277 static bool isKind(const SVal& V) {
278 return V.getBaseKind() == NonLocKind;
282 class Loc : public DefinedSVal {
285 explicit Loc(unsigned SubKind, const void *D)
286 : DefinedSVal(const_cast<void*>(D), true, SubKind) {}
289 void dumpToStream(raw_ostream &Out) const;
291 static inline bool isLocType(QualType T) {
292 return T->isAnyPointerType() || T->isBlockPointerType() ||
293 T->isReferenceType() || T->isNullPtrType();
298 static bool isKind(const SVal& V) {
299 return V.getBaseKind() == LocKind;
303 //==------------------------------------------------------------------------==//
304 // Subclasses of NonLoc.
305 //==------------------------------------------------------------------------==//
309 enum Kind { ConcreteIntKind, SymbolValKind,
310 LocAsIntegerKind, CompoundValKind, LazyCompoundValKind };
312 /// \brief Represents symbolic expression.
313 class SymbolVal : public NonLoc {
315 SymbolVal(SymbolRef sym) : NonLoc(SymbolValKind, sym) {}
317 SymbolRef getSymbol() const {
318 return (const SymExpr*) Data;
321 bool isExpression() const {
322 return !isa<SymbolData>(getSymbol());
328 static bool isKind(const SVal& V) {
329 return V.getBaseKind() == NonLocKind &&
330 V.getSubKind() == SymbolValKind;
333 static bool isKind(const NonLoc& V) {
334 return V.getSubKind() == SymbolValKind;
338 /// \brief Value representing integer constant.
339 class ConcreteInt : public NonLoc {
341 explicit ConcreteInt(const llvm::APSInt& V) : NonLoc(ConcreteIntKind, &V) {}
343 const llvm::APSInt& getValue() const {
344 return *static_cast<const llvm::APSInt*>(Data);
347 // Transfer functions for binary/unary operations on ConcreteInts.
348 SVal evalBinOp(SValBuilder &svalBuilder, BinaryOperator::Opcode Op,
349 const ConcreteInt& R) const;
351 ConcreteInt evalComplement(SValBuilder &svalBuilder) const;
353 ConcreteInt evalMinus(SValBuilder &svalBuilder) const;
358 static bool isKind(const SVal& V) {
359 return V.getBaseKind() == NonLocKind &&
360 V.getSubKind() == ConcreteIntKind;
363 static bool isKind(const NonLoc& V) {
364 return V.getSubKind() == ConcreteIntKind;
368 class LocAsInteger : public NonLoc {
369 friend class ento::SValBuilder;
371 explicit LocAsInteger(const std::pair<SVal, uintptr_t> &data)
372 : NonLoc(LocAsIntegerKind, &data) {
373 assert (data.first.getAs<Loc>());
379 const std::pair<SVal, uintptr_t> *D =
380 static_cast<const std::pair<SVal, uintptr_t> *>(Data);
381 return D->first.castAs<Loc>();
384 Loc getPersistentLoc() const {
385 const std::pair<SVal, uintptr_t> *D =
386 static_cast<const std::pair<SVal, uintptr_t> *>(Data);
387 const SVal& V = D->first;
388 return V.castAs<Loc>();
391 unsigned getNumBits() const {
392 const std::pair<SVal, uintptr_t> *D =
393 static_cast<const std::pair<SVal, uintptr_t> *>(Data);
400 static bool isKind(const SVal& V) {
401 return V.getBaseKind() == NonLocKind &&
402 V.getSubKind() == LocAsIntegerKind;
405 static bool isKind(const NonLoc& V) {
406 return V.getSubKind() == LocAsIntegerKind;
410 class CompoundVal : public NonLoc {
411 friend class ento::SValBuilder;
413 explicit CompoundVal(const CompoundValData* D) : NonLoc(CompoundValKind, D) {}
416 const CompoundValData* getValue() const {
417 return static_cast<const CompoundValData*>(Data);
420 typedef llvm::ImmutableList<SVal>::iterator iterator;
421 iterator begin() const;
422 iterator end() const;
427 static bool isKind(const SVal& V) {
428 return V.getBaseKind() == NonLocKind && V.getSubKind() == CompoundValKind;
431 static bool isKind(const NonLoc& V) {
432 return V.getSubKind() == CompoundValKind;
436 class LazyCompoundVal : public NonLoc {
437 friend class ento::SValBuilder;
439 explicit LazyCompoundVal(const LazyCompoundValData *D)
440 : NonLoc(LazyCompoundValKind, D) {}
442 const LazyCompoundValData *getCVData() const {
443 return static_cast<const LazyCompoundValData*>(Data);
445 const void *getStore() const;
446 const TypedValueRegion *getRegion() const;
451 static bool isKind(const SVal& V) {
452 return V.getBaseKind() == NonLocKind &&
453 V.getSubKind() == LazyCompoundValKind;
455 static bool isKind(const NonLoc& V) {
456 return V.getSubKind() == LazyCompoundValKind;
460 } // end namespace ento::nonloc
462 //==------------------------------------------------------------------------==//
463 // Subclasses of Loc.
464 //==------------------------------------------------------------------------==//
468 enum Kind { GotoLabelKind, MemRegionKind, ConcreteIntKind };
470 class GotoLabel : public Loc {
472 explicit GotoLabel(LabelDecl *Label) : Loc(GotoLabelKind, Label) {}
474 const LabelDecl *getLabel() const {
475 return static_cast<const LabelDecl*>(Data);
481 static bool isKind(const SVal& V) {
482 return V.getBaseKind() == LocKind && V.getSubKind() == GotoLabelKind;
485 static bool isKind(const Loc& V) {
486 return V.getSubKind() == GotoLabelKind;
491 class MemRegionVal : public Loc {
493 explicit MemRegionVal(const MemRegion* r) : Loc(MemRegionKind, r) {}
495 /// \brief Get the underlining region.
496 const MemRegion* getRegion() const {
497 return static_cast<const MemRegion*>(Data);
500 /// \brief Get the underlining region and strip casts.
501 const MemRegion* stripCasts(bool StripBaseCasts = true) const;
503 template <typename REGION>
504 const REGION* getRegionAs() const {
505 return dyn_cast<REGION>(getRegion());
508 inline bool operator==(const MemRegionVal& R) const {
509 return getRegion() == R.getRegion();
512 inline bool operator!=(const MemRegionVal& R) const {
513 return getRegion() != R.getRegion();
519 static bool isKind(const SVal& V) {
520 return V.getBaseKind() == LocKind &&
521 V.getSubKind() == MemRegionKind;
524 static bool isKind(const Loc& V) {
525 return V.getSubKind() == MemRegionKind;
529 class ConcreteInt : public Loc {
531 explicit ConcreteInt(const llvm::APSInt& V) : Loc(ConcreteIntKind, &V) {}
533 const llvm::APSInt& getValue() const {
534 return *static_cast<const llvm::APSInt*>(Data);
537 // Transfer functions for binary/unary operations on ConcreteInts.
538 SVal evalBinOp(BasicValueFactory& BasicVals, BinaryOperator::Opcode Op,
539 const ConcreteInt& R) const;
544 static bool isKind(const SVal& V) {
545 return V.getBaseKind() == LocKind &&
546 V.getSubKind() == ConcreteIntKind;
549 static bool isKind(const Loc& V) {
550 return V.getSubKind() == ConcreteIntKind;
554 } // end ento::loc namespace
556 } // end ento namespace
558 } // end clang namespace
561 static inline raw_ostream &operator<<(raw_ostream &os,
562 clang::ento::SVal V) {
567 template <typename T> struct isPodLike;
568 template <> struct isPodLike<clang::ento::SVal> {
569 static const bool value = true;
572 } // end llvm namespace