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