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:
CompoundValData(QualType t,llvm::ImmutableList<SVal> l)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 
begin()52   iterator begin() const { return L.begin(); }
end()53   iterator end() const { return L.end(); }
54 
55   static void Profile(llvm::FoldingSetNodeID& ID, QualType T,
56                       llvm::ImmutableList<SVal> L);
57 
Profile(llvm::FoldingSetNodeID & ID)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:
LazyCompoundValData(const StoreRef & st,const TypedValueRegion * r)66   LazyCompoundValData(const StoreRef &st, const TypedValueRegion *r)
67       : store(st), region(r) {
68     assert(NonLoc::isCompoundType(r->getValueType()));
69   }
70 
getStore()71   const void *getStore() const { return store.getStore(); }
getRegion()72   const TypedValueRegion *getRegion() const { return region; }
73 
74   static void Profile(llvm::FoldingSetNodeID& ID,
75                       const StoreRef &store,
76                       const TypedValueRegion *region);
77 
Profile(llvm::FoldingSetNodeID & ID)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:
PointerToMemberData(const NamedDecl * D,llvm::ImmutableList<const CXXBaseSpecifier * > L)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 
begin()92   iterator begin() const { return L.begin(); }
end()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 
Profile(llvm::FoldingSetNodeID & ID)98   void Profile(llvm::FoldingSetNodeID &ID) { Profile(ID, D, L); }
getDeclaratorDecl()99   const NamedDecl *getDeclaratorDecl() const { return D; }
100 
getCXXBaseList()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:
BasicValueFactory(ASTContext & ctx,llvm::BumpPtrAllocator & Alloc)128   BasicValueFactory(ASTContext &ctx, llvm::BumpPtrAllocator &Alloc)
129       : Ctx(ctx), BPAlloc(Alloc), SValListFactory(Alloc),
130         CXXBaseListFactory(Alloc) {}
131 
132   ~BasicValueFactory();
133 
getContext()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.
getAPSIntType(QualType T)141   APSIntType getAPSIntType(QualType T) const {
142     // For the purposes of the analysis and constraints, we treat atomics
143     // as their underlying types.
144     if (const AtomicType *AT = T->getAs<AtomicType>()) {
145       T = AT->getValueType();
146     }
147 
148     assert(T->isIntegralOrEnumerationType() || Loc::isLocType(T));
149     return APSIntType(Ctx.getIntWidth(T),
150                       !T->isSignedIntegerOrEnumerationType());
151   }
152 
153   /// Convert - Create a new persistent APSInt with the same value as 'From'
154   ///  but with the bitwidth and signedness of 'To'.
Convert(const llvm::APSInt & To,const llvm::APSInt & From)155   const llvm::APSInt &Convert(const llvm::APSInt& To,
156                               const llvm::APSInt& From) {
157     APSIntType TargetType(To);
158     if (TargetType == APSIntType(From))
159       return From;
160 
161     return getValue(TargetType.convert(From));
162   }
163 
Convert(QualType T,const llvm::APSInt & From)164   const llvm::APSInt &Convert(QualType T, const llvm::APSInt &From) {
165     APSIntType TargetType = getAPSIntType(T);
166     return Convert(TargetType, From);
167   }
168 
Convert(APSIntType TargetType,const llvm::APSInt & From)169   const llvm::APSInt &Convert(APSIntType TargetType, const llvm::APSInt &From) {
170     if (TargetType == APSIntType(From))
171       return From;
172 
173     return getValue(TargetType.convert(From));
174   }
175 
getIntValue(uint64_t X,bool isUnsigned)176   const llvm::APSInt &getIntValue(uint64_t X, bool isUnsigned) {
177     QualType T = isUnsigned ? Ctx.UnsignedIntTy : Ctx.IntTy;
178     return getValue(X, T);
179   }
180 
getMaxValue(const llvm::APSInt & v)181   const llvm::APSInt &getMaxValue(const llvm::APSInt &v) {
182     return getValue(APSIntType(v).getMaxValue());
183   }
184 
getMinValue(const llvm::APSInt & v)185   const llvm::APSInt &getMinValue(const llvm::APSInt &v) {
186     return getValue(APSIntType(v).getMinValue());
187   }
188 
getMaxValue(QualType T)189   const llvm::APSInt &getMaxValue(QualType T) {
190     return getMaxValue(getAPSIntType(T));
191   }
192 
getMinValue(QualType T)193   const llvm::APSInt &getMinValue(QualType T) {
194     return getMinValue(getAPSIntType(T));
195   }
196 
getMaxValue(APSIntType T)197   const llvm::APSInt &getMaxValue(APSIntType T) {
198     return getValue(T.getMaxValue());
199   }
200 
getMinValue(APSIntType T)201   const llvm::APSInt &getMinValue(APSIntType T) {
202     return getValue(T.getMinValue());
203   }
204 
Add1(const llvm::APSInt & V)205   const llvm::APSInt &Add1(const llvm::APSInt &V) {
206     llvm::APSInt X = V;
207     ++X;
208     return getValue(X);
209   }
210 
Sub1(const llvm::APSInt & V)211   const llvm::APSInt &Sub1(const llvm::APSInt &V) {
212     llvm::APSInt X = V;
213     --X;
214     return getValue(X);
215   }
216 
getZeroWithTypeSize(QualType T)217   const llvm::APSInt &getZeroWithTypeSize(QualType T) {
218     assert(T->isScalarType());
219     return getValue(0, Ctx.getTypeSize(T), true);
220   }
221 
222   const llvm::APSInt &getZeroWithPtrWidth(bool isUnsigned = true) {
223     return getValue(0, Ctx.getTypeSize(Ctx.VoidPtrTy), isUnsigned);
224   }
225 
getIntWithPtrWidth(uint64_t X,bool isUnsigned)226   const llvm::APSInt &getIntWithPtrWidth(uint64_t X, bool isUnsigned) {
227     return getValue(X, Ctx.getTypeSize(Ctx.VoidPtrTy), isUnsigned);
228   }
229 
getTruthValue(bool b,QualType T)230   const llvm::APSInt &getTruthValue(bool b, QualType T) {
231     return getValue(b ? 1 : 0, Ctx.getIntWidth(T),
232                     T->isUnsignedIntegerOrEnumerationType());
233   }
234 
getTruthValue(bool b)235   const llvm::APSInt &getTruthValue(bool b) {
236     return getTruthValue(b, Ctx.getLogicalOperationType());
237   }
238 
239   const CompoundValData *getCompoundValData(QualType T,
240                                             llvm::ImmutableList<SVal> Vals);
241 
242   const LazyCompoundValData *getLazyCompoundValData(const StoreRef &store,
243                                             const TypedValueRegion *region);
244 
245   const PointerToMemberData *
246   getPointerToMemberData(const NamedDecl *ND,
247                          llvm::ImmutableList<const CXXBaseSpecifier *> L);
248 
getEmptySValList()249   llvm::ImmutableList<SVal> getEmptySValList() {
250     return SValListFactory.getEmptyList();
251   }
252 
prependSVal(SVal X,llvm::ImmutableList<SVal> L)253   llvm::ImmutableList<SVal> prependSVal(SVal X, llvm::ImmutableList<SVal> L) {
254     return SValListFactory.add(X, L);
255   }
256 
getEmptyCXXBaseList()257   llvm::ImmutableList<const CXXBaseSpecifier *> getEmptyCXXBaseList() {
258     return CXXBaseListFactory.getEmptyList();
259   }
260 
prependCXXBase(const CXXBaseSpecifier * CBS,llvm::ImmutableList<const CXXBaseSpecifier * > L)261   llvm::ImmutableList<const CXXBaseSpecifier *> prependCXXBase(
262       const CXXBaseSpecifier *CBS,
263       llvm::ImmutableList<const CXXBaseSpecifier *> L) {
264     return CXXBaseListFactory.add(CBS, L);
265   }
266 
267   const PointerToMemberData *
268   accumCXXBase(llvm::iterator_range<CastExpr::path_const_iterator> PathRange,
269                const nonloc::PointerToMember &PTM, const clang::CastKind &kind);
270 
271   const llvm::APSInt* evalAPSInt(BinaryOperator::Opcode Op,
272                                      const llvm::APSInt& V1,
273                                      const llvm::APSInt& V2);
274 
275   const std::pair<SVal, uintptr_t>&
276   getPersistentSValWithData(const SVal& V, uintptr_t Data);
277 
278   const std::pair<SVal, SVal>&
279   getPersistentSValPair(const SVal& V1, const SVal& V2);
280 
281   const SVal* getPersistentSVal(SVal X);
282 };
283 
284 } // namespace ento
285 
286 } // namespace clang
287 
288 #endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_BASICVALUEFACTORY_H
289