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
34namespace clang {
35
36class CXXBaseSpecifier;
37
38namespace ento {
39
40class CompoundValData : public llvm::FoldingSetNode {
41  QualType T;
42  llvm::ImmutableList<SVal> L;
43
44public:
45  CompoundValData(QualType t, llvm::ImmutableList<SVal> l) : T(t), L(l) {
46    assert(NonLoc::isCompoundType(t));
47  }
48
49  using iterator = llvm::ImmutableList<SVal>::iterator;
50
51  iterator begin() const { return L.begin(); }
52  iterator end() const { return L.end(); }
53
54  QualType getType() const { return T; }
55
56  static void Profile(llvm::FoldingSetNodeID& ID, QualType T,
57                      llvm::ImmutableList<SVal> L);
58
59  void Profile(llvm::FoldingSetNodeID& ID) { Profile(ID, T, L); }
60};
61
62class LazyCompoundValData : public llvm::FoldingSetNode {
63  StoreRef store;
64  const TypedValueRegion *region;
65
66public:
67  LazyCompoundValData(const StoreRef &st, const TypedValueRegion *r)
68      : store(st), region(r) {
69    assert(r);
70    assert(NonLoc::isCompoundType(r->getValueType()));
71  }
72
73  /// It might return null.
74  const void *getStore() const { return store.getStore(); }
75
76  LLVM_ATTRIBUTE_RETURNS_NONNULL
77  const TypedValueRegion *getRegion() const { return region; }
78
79  static void Profile(llvm::FoldingSetNodeID& ID,
80                      const StoreRef &store,
81                      const TypedValueRegion *region);
82
83  void Profile(llvm::FoldingSetNodeID& ID) { Profile(ID, store, region); }
84};
85
86class PointerToMemberData : public llvm::FoldingSetNode {
87  const NamedDecl *D;
88  llvm::ImmutableList<const CXXBaseSpecifier *> L;
89
90public:
91  PointerToMemberData(const NamedDecl *D,
92                      llvm::ImmutableList<const CXXBaseSpecifier *> L)
93      : D(D), L(L) {}
94
95  using iterator = llvm::ImmutableList<const CXXBaseSpecifier *>::iterator;
96
97  iterator begin() const { return L.begin(); }
98  iterator end() const { return L.end(); }
99
100  static void Profile(llvm::FoldingSetNodeID &ID, const NamedDecl *D,
101                      llvm::ImmutableList<const CXXBaseSpecifier *> L);
102
103  void Profile(llvm::FoldingSetNodeID &ID) { Profile(ID, D, L); }
104
105  /// It might return null.
106  const NamedDecl *getDeclaratorDecl() const { return D; }
107
108  llvm::ImmutableList<const CXXBaseSpecifier *> getCXXBaseList() const {
109    return L;
110  }
111};
112
113class BasicValueFactory {
114  using APSIntSetTy =
115      llvm::FoldingSet<llvm::FoldingSetNodeWrapper<llvm::APSInt>>;
116
117  ASTContext &Ctx;
118  llvm::BumpPtrAllocator& BPAlloc;
119
120  APSIntSetTy APSIntSet;
121  void *PersistentSVals = nullptr;
122  void *PersistentSValPairs = nullptr;
123
124  llvm::ImmutableList<SVal>::Factory SValListFactory;
125  llvm::ImmutableList<const CXXBaseSpecifier *>::Factory CXXBaseListFactory;
126  llvm::FoldingSet<CompoundValData>  CompoundValDataSet;
127  llvm::FoldingSet<LazyCompoundValData> LazyCompoundValDataSet;
128  llvm::FoldingSet<PointerToMemberData> PointerToMemberDataSet;
129
130  // This is private because external clients should use the factory
131  // method that takes a QualType.
132  const llvm::APSInt& getValue(uint64_t X, unsigned BitWidth, bool isUnsigned);
133
134public:
135  BasicValueFactory(ASTContext &ctx, llvm::BumpPtrAllocator &Alloc)
136      : Ctx(ctx), BPAlloc(Alloc), SValListFactory(Alloc),
137        CXXBaseListFactory(Alloc) {}
138
139  ~BasicValueFactory();
140
141  ASTContext &getContext() const { return Ctx; }
142
143  const llvm::APSInt& getValue(const llvm::APSInt& X);
144  const llvm::APSInt& getValue(const llvm::APInt& X, bool isUnsigned);
145  const llvm::APSInt& getValue(uint64_t X, QualType T);
146
147  /// Returns the type of the APSInt used to store values of the given QualType.
148  APSIntType getAPSIntType(QualType T) const {
149    // For the purposes of the analysis and constraints, we treat atomics
150    // as their underlying types.
151    if (const AtomicType *AT = T->getAs<AtomicType>()) {
152      T = AT->getValueType();
153    }
154
155    if (T->isIntegralOrEnumerationType() || Loc::isLocType(T)) {
156      return APSIntType(Ctx.getIntWidth(T),
157                        !T->isSignedIntegerOrEnumerationType());
158    } else {
159      // implicitly handle case of T->isFixedPointType()
160      return APSIntType(Ctx.getIntWidth(T), T->isUnsignedFixedPointType());
161    }
162
163    llvm_unreachable("Unsupported type in getAPSIntType!");
164  }
165
166  /// Convert - Create a new persistent APSInt with the same value as 'From'
167  ///  but with the bitwidth and signedness of 'To'.
168  const llvm::APSInt &Convert(const llvm::APSInt& To,
169                              const llvm::APSInt& From) {
170    APSIntType TargetType(To);
171    if (TargetType == APSIntType(From))
172      return From;
173
174    return getValue(TargetType.convert(From));
175  }
176
177  const llvm::APSInt &Convert(QualType T, const llvm::APSInt &From) {
178    APSIntType TargetType = getAPSIntType(T);
179    return Convert(TargetType, From);
180  }
181
182  const llvm::APSInt &Convert(APSIntType TargetType, const llvm::APSInt &From) {
183    if (TargetType == APSIntType(From))
184      return From;
185
186    return getValue(TargetType.convert(From));
187  }
188
189  const llvm::APSInt &getIntValue(uint64_t X, bool isUnsigned) {
190    QualType T = isUnsigned ? Ctx.UnsignedIntTy : Ctx.IntTy;
191    return getValue(X, T);
192  }
193
194  const llvm::APSInt &getMaxValue(const llvm::APSInt &v) {
195    return getValue(APSIntType(v).getMaxValue());
196  }
197
198  const llvm::APSInt &getMinValue(const llvm::APSInt &v) {
199    return getValue(APSIntType(v).getMinValue());
200  }
201
202  const llvm::APSInt &getMaxValue(QualType T) {
203    return getMaxValue(getAPSIntType(T));
204  }
205
206  const llvm::APSInt &getMinValue(QualType T) {
207    return getMinValue(getAPSIntType(T));
208  }
209
210  const llvm::APSInt &getMaxValue(APSIntType T) {
211    return getValue(T.getMaxValue());
212  }
213
214  const llvm::APSInt &getMinValue(APSIntType T) {
215    return getValue(T.getMinValue());
216  }
217
218  const llvm::APSInt &Add1(const llvm::APSInt &V) {
219    llvm::APSInt X = V;
220    ++X;
221    return getValue(X);
222  }
223
224  const llvm::APSInt &Sub1(const llvm::APSInt &V) {
225    llvm::APSInt X = V;
226    --X;
227    return getValue(X);
228  }
229
230  const llvm::APSInt &getZeroWithTypeSize(QualType T) {
231    assert(T->isScalarType());
232    return getValue(0, Ctx.getTypeSize(T), true);
233  }
234
235  const llvm::APSInt &getTruthValue(bool b, QualType T) {
236    return getValue(b ? 1 : 0, Ctx.getIntWidth(T),
237                    T->isUnsignedIntegerOrEnumerationType());
238  }
239
240  const llvm::APSInt &getTruthValue(bool b) {
241    return getTruthValue(b, Ctx.getLogicalOperationType());
242  }
243
244  const CompoundValData *getCompoundValData(QualType T,
245                                            llvm::ImmutableList<SVal> Vals);
246
247  const LazyCompoundValData *getLazyCompoundValData(const StoreRef &store,
248                                            const TypedValueRegion *region);
249
250  const PointerToMemberData *
251  getPointerToMemberData(const NamedDecl *ND,
252                         llvm::ImmutableList<const CXXBaseSpecifier *> L);
253
254  llvm::ImmutableList<SVal> getEmptySValList() {
255    return SValListFactory.getEmptyList();
256  }
257
258  llvm::ImmutableList<SVal> prependSVal(SVal X, llvm::ImmutableList<SVal> L) {
259    return SValListFactory.add(X, L);
260  }
261
262  llvm::ImmutableList<const CXXBaseSpecifier *> getEmptyCXXBaseList() {
263    return CXXBaseListFactory.getEmptyList();
264  }
265
266  llvm::ImmutableList<const CXXBaseSpecifier *> prependCXXBase(
267      const CXXBaseSpecifier *CBS,
268      llvm::ImmutableList<const CXXBaseSpecifier *> L) {
269    return CXXBaseListFactory.add(CBS, L);
270  }
271
272  const PointerToMemberData *
273  accumCXXBase(llvm::iterator_range<CastExpr::path_const_iterator> PathRange,
274               const nonloc::PointerToMember &PTM, const clang::CastKind &kind);
275
276  const llvm::APSInt* evalAPSInt(BinaryOperator::Opcode Op,
277                                     const llvm::APSInt& V1,
278                                     const llvm::APSInt& V2);
279
280  const std::pair<SVal, uintptr_t>&
281  getPersistentSValWithData(const SVal& V, uintptr_t Data);
282
283  const std::pair<SVal, SVal>&
284  getPersistentSValPair(const SVal& V1, const SVal& V2);
285
286  const SVal* getPersistentSVal(SVal X);
287};
288
289} // namespace ento
290
291} // namespace clang
292
293#endif // LLVM_CLANG_STATICANALYZER_CORE_PATHSENSITIVE_BASICVALUEFACTORY_H
294