xref: /llvm-project/clang/include/clang/StaticAnalyzer/Core/PathSensitive/BasicValueFactory.h (revision b41240be6b9e58687011b2bd1b942c6625cbb5ad) 
1 //==- BasicValueFactory.h - Basic values for Path Sens analysis --*- C++ -*-==//
2 //
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
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 //  This file defines BasicValueFactory, a class that manages the lifetime
10 //  of APSInt objects and symbolic constraints used by ExprEngine
11 //  and related classes.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_BASICVALUEFACTORY_H
16 #define LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_BASICVALUEFACTORY_H
17 
18 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/Type.h"
21 #include "clang/StaticAnalyzer/Core/PathSensitive/APSIntPtr.h"
22 #include "clang/StaticAnalyzer/Core/PathSensitive/APSIntType.h"
23 #include "clang/StaticAnalyzer/Core/PathSensitive/MemRegion.h"
24 #include "clang/StaticAnalyzer/Core/PathSensitive/SVals.h"
25 #include "clang/StaticAnalyzer/Core/PathSensitive/StoreRef.h"
26 #include "llvm/ADT/APSInt.h"
27 #include "llvm/ADT/FoldingSet.h"
28 #include "llvm/ADT/ImmutableList.h"
29 #include "llvm/ADT/iterator_range.h"
30 #include "llvm/Support/Allocator.h"
31 #include <cassert>
32 #include <cstdint>
33 #include <utility>
34 
35 namespace clang {
36 
37 class CXXBaseSpecifier;
38 
39 namespace ento {
40 
41 class CompoundValData : public llvm::FoldingSetNode {
42   QualType T;
43   llvm::ImmutableList<SVal> L;
44 
45 public:
46   CompoundValData(QualType t, llvm::ImmutableList<SVal> l) : T(t), L(l) {
47     assert(NonLoc::isCompoundType(t));
48   }
49 
50   using iterator = llvm::ImmutableList<SVal>::iterator;
51 
52   iterator begin() const { return L.begin(); }
53   iterator end() const { return L.end(); }
54 
55   QualType getType() const { return T; }
56 
57   static void Profile(llvm::FoldingSetNodeID& ID, QualType T,
58                       llvm::ImmutableList<SVal> L);
59 
60   void Profile(llvm::FoldingSetNodeID& ID) { Profile(ID, T, L); }
61 };
62 
63 class LazyCompoundValData : public llvm::FoldingSetNode {
64   StoreRef store;
65   const TypedValueRegion *region;
66 
67 public:
68   LazyCompoundValData(const StoreRef &st, const TypedValueRegion *r)
69       : store(st), region(r) {
70     assert(r);
71     assert(NonLoc::isCompoundType(r->getValueType()));
72   }
73 
74   /// It might return null.
75   const void *getStore() const { return store.getStore(); }
76 
77   LLVM_ATTRIBUTE_RETURNS_NONNULL
78   const TypedValueRegion *getRegion() const { return region; }
79 
80   static void Profile(llvm::FoldingSetNodeID& ID,
81                       const StoreRef &store,
82                       const TypedValueRegion *region);
83 
84   void Profile(llvm::FoldingSetNodeID& ID) { Profile(ID, store, region); }
85 };
86 
87 class PointerToMemberData : public llvm::FoldingSetNode {
88   const NamedDecl *D;
89   llvm::ImmutableList<const CXXBaseSpecifier *> L;
90 
91 public:
92   PointerToMemberData(const NamedDecl *D,
93                       llvm::ImmutableList<const CXXBaseSpecifier *> L)
94       : D(D), L(L) {}
95 
96   using iterator = llvm::ImmutableList<const CXXBaseSpecifier *>::iterator;
97 
98   iterator begin() const { return L.begin(); }
99   iterator end() const { return L.end(); }
100 
101   static void Profile(llvm::FoldingSetNodeID &ID, const NamedDecl *D,
102                       llvm::ImmutableList<const CXXBaseSpecifier *> L);
103 
104   void Profile(llvm::FoldingSetNodeID &ID) { Profile(ID, D, L); }
105 
106   /// It might return null.
107   const NamedDecl *getDeclaratorDecl() const { return D; }
108 
109   llvm::ImmutableList<const CXXBaseSpecifier *> getCXXBaseList() const {
110     return L;
111   }
112 };
113 
114 class BasicValueFactory {
115   using APSIntSetTy =
116       llvm::FoldingSet<llvm::FoldingSetNodeWrapper<llvm::APSInt>>;
117 
118   ASTContext &Ctx;
119   llvm::BumpPtrAllocator& BPAlloc;
120 
121   APSIntSetTy APSIntSet;
122   void *PersistentSVals = nullptr;
123   void *PersistentSValPairs = nullptr;
124 
125   llvm::ImmutableList<SVal>::Factory SValListFactory;
126   llvm::ImmutableList<const CXXBaseSpecifier *>::Factory CXXBaseListFactory;
127   llvm::FoldingSet<CompoundValData>  CompoundValDataSet;
128   llvm::FoldingSet<LazyCompoundValData> LazyCompoundValDataSet;
129   llvm::FoldingSet<PointerToMemberData> PointerToMemberDataSet;
130 
131   // This is private because external clients should use the factory
132   // method that takes a QualType.
133   APSIntPtr getValue(uint64_t X, unsigned BitWidth, bool isUnsigned);
134 
135 public:
136   BasicValueFactory(ASTContext &ctx, llvm::BumpPtrAllocator &Alloc)
137       : Ctx(ctx), BPAlloc(Alloc), SValListFactory(Alloc),
138         CXXBaseListFactory(Alloc) {}
139 
140   ~BasicValueFactory();
141 
142   ASTContext &getContext() const { return Ctx; }
143 
144   APSIntPtr getValue(const llvm::APSInt &X);
145   APSIntPtr getValue(const llvm::APInt &X, bool isUnsigned);
146   APSIntPtr getValue(uint64_t X, QualType T);
147 
148   /// Returns the type of the APSInt used to store values of the given QualType.
149   APSIntType getAPSIntType(QualType T) const {
150     // For the purposes of the analysis and constraints, we treat atomics
151     // as their underlying types.
152     if (const AtomicType *AT = T->getAs<AtomicType>()) {
153       T = AT->getValueType();
154     }
155 
156     if (T->isIntegralOrEnumerationType() || Loc::isLocType(T)) {
157       return APSIntType(Ctx.getIntWidth(T),
158                         !T->isSignedIntegerOrEnumerationType());
159     } else {
160       // implicitly handle case of T->isFixedPointType()
161       return APSIntType(Ctx.getIntWidth(T), T->isUnsignedFixedPointType());
162     }
163 
164     llvm_unreachable("Unsupported type in getAPSIntType!");
165   }
166 
167   /// Convert - Create a new persistent APSInt with the same value as 'From'
168   ///  but with the bitwidth and signedness of 'To'.
169   APSIntPtr Convert(const llvm::APSInt &To, const llvm::APSInt &From) {
170     APSIntType TargetType(To);
171     if (TargetType == APSIntType(From))
172       return getValue(From);
173 
174     return getValue(TargetType.convert(From));
175   }
176 
177   APSIntPtr Convert(QualType T, const llvm::APSInt &From) {
178     APSIntType TargetType = getAPSIntType(T);
179     return Convert(TargetType, From);
180   }
181 
182   APSIntPtr Convert(APSIntType TargetType, const llvm::APSInt &From) {
183     if (TargetType == APSIntType(From))
184       return getValue(From);
185 
186     return getValue(TargetType.convert(From));
187   }
188 
189   APSIntPtr getIntValue(uint64_t X, bool isUnsigned) {
190     QualType T = isUnsigned ? Ctx.UnsignedIntTy : Ctx.IntTy;
191     return getValue(X, T);
192   }
193 
194   APSIntPtr getMaxValue(const llvm::APSInt &v) {
195     return getValue(APSIntType(v).getMaxValue());
196   }
197 
198   APSIntPtr getMinValue(const llvm::APSInt &v) {
199     return getValue(APSIntType(v).getMinValue());
200   }
201 
202   APSIntPtr getMaxValue(QualType T) { return getMaxValue(getAPSIntType(T)); }
203 
204   APSIntPtr getMinValue(QualType T) { return getMinValue(getAPSIntType(T)); }
205 
206   APSIntPtr getMaxValue(APSIntType T) { return getValue(T.getMaxValue()); }
207 
208   APSIntPtr getMinValue(APSIntType T) { return getValue(T.getMinValue()); }
209 
210   APSIntPtr Add1(const llvm::APSInt &V) {
211     llvm::APSInt X = V;
212     ++X;
213     return getValue(X);
214   }
215 
216   APSIntPtr Sub1(const llvm::APSInt &V) {
217     llvm::APSInt X = V;
218     --X;
219     return getValue(X);
220   }
221 
222   APSIntPtr getZeroWithTypeSize(QualType T) {
223     assert(T->isScalarType());
224     return getValue(0, Ctx.getTypeSize(T), true);
225   }
226 
227   APSIntPtr getTruthValue(bool b, QualType T) {
228     return getValue(b ? 1 : 0, Ctx.getIntWidth(T),
229                     T->isUnsignedIntegerOrEnumerationType());
230   }
231 
232   APSIntPtr getTruthValue(bool b) {
233     return getTruthValue(b, Ctx.getLogicalOperationType());
234   }
235 
236   const CompoundValData *getCompoundValData(QualType T,
237                                             llvm::ImmutableList<SVal> Vals);
238 
239   const LazyCompoundValData *getLazyCompoundValData(const StoreRef &store,
240                                             const TypedValueRegion *region);
241 
242   const PointerToMemberData *
243   getPointerToMemberData(const NamedDecl *ND,
244                          llvm::ImmutableList<const CXXBaseSpecifier *> L);
245 
246   llvm::ImmutableList<SVal> getEmptySValList() {
247     return SValListFactory.getEmptyList();
248   }
249 
250   llvm::ImmutableList<SVal> prependSVal(SVal X, llvm::ImmutableList<SVal> L) {
251     return SValListFactory.add(X, L);
252   }
253 
254   llvm::ImmutableList<const CXXBaseSpecifier *> getEmptyCXXBaseList() {
255     return CXXBaseListFactory.getEmptyList();
256   }
257 
258   llvm::ImmutableList<const CXXBaseSpecifier *> prependCXXBase(
259       const CXXBaseSpecifier *CBS,
260       llvm::ImmutableList<const CXXBaseSpecifier *> L) {
261     return CXXBaseListFactory.add(CBS, L);
262   }
263 
264   const PointerToMemberData *
265   accumCXXBase(llvm::iterator_range<CastExpr::path_const_iterator> PathRange,
266                const nonloc::PointerToMember &PTM, const clang::CastKind &kind);
267 
268   std::optional<APSIntPtr> evalAPSInt(BinaryOperator::Opcode Op,
269                                       const llvm::APSInt &V1,
270                                       const llvm::APSInt &V2);
271 
272   const std::pair<SVal, uintptr_t>&
273   getPersistentSValWithData(const SVal& V, uintptr_t Data);
274 
275   const std::pair<SVal, SVal>&
276   getPersistentSValPair(const SVal& V1, const SVal& V2);
277 
278   const SVal* getPersistentSVal(SVal X);
279 };
280 
281 } // namespace ento
282 
283 } // namespace clang
284 
285 #endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_BASICVALUEFACTORY_H
286