1 //===- Sanitizers.h - C Language Family Language Options --------*- 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 /// \file
10 /// Defines the clang::SanitizerKind enum.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_CLANG_BASIC_SANITIZERS_H
15 #define LLVM_CLANG_BASIC_SANITIZERS_H
16 
17 #include "clang/Basic/LLVM.h"
18 #include "llvm/ADT/StringRef.h"
19 #include "llvm/Support/MathExtras.h"
20 #include <cassert>
21 #include <cstdint>
22 
23 namespace llvm {
24 class hash_code;
25 }
26 
27 namespace clang {
28 
29 class SanitizerMask {
30   // NOTE: this class assumes kNumElem == 2 in most of the constexpr functions,
31   // in order to work within the C++11 constexpr function constraints. If you
32   // change kNumElem, you'll need to update those member functions as well.
33 
34   /// Number of array elements.
35   static constexpr unsigned kNumElem = 2;
36   /// Mask value initialized to 0.
37   uint64_t maskLoToHigh[kNumElem]{};
38   /// Number of bits in a mask.
39   static constexpr unsigned kNumBits = sizeof(decltype(maskLoToHigh)) * 8;
40   /// Number of bits in a mask element.
41   static constexpr unsigned kNumBitElem = sizeof(decltype(maskLoToHigh[0])) * 8;
42 
43   constexpr SanitizerMask(uint64_t mask1, uint64_t mask2)
44       : maskLoToHigh{mask1, mask2} {}
45 
46 public:
47   SanitizerMask() = default;
48 
49   static constexpr bool checkBitPos(const unsigned Pos) {
50     return Pos < kNumBits;
51   }
52 
53   /// Create a mask with a bit enabled at position Pos.
54   static constexpr SanitizerMask bitPosToMask(const unsigned Pos) {
55     uint64_t mask1 = (Pos < kNumBitElem) ? 1ULL << (Pos % kNumBitElem) : 0;
56     uint64_t mask2 = (Pos >= kNumBitElem && Pos < (kNumBitElem * 2))
57                          ? 1ULL << (Pos % kNumBitElem)
58                          : 0;
59     return SanitizerMask(mask1, mask2);
60   }
61 
62   unsigned countPopulation() const {
63     unsigned total = 0;
64     for (const auto &Val : maskLoToHigh)
65       total += llvm::countPopulation(Val);
66     return total;
67   }
68 
69   void flipAllBits() {
70     for (auto &Val : maskLoToHigh)
71       Val = ~Val;
72   }
73 
74   bool isPowerOf2() const {
75     return countPopulation() == 1;
76   }
77 
78   llvm::hash_code hash_value() const;
79 
80   constexpr explicit operator bool() const {
81     return maskLoToHigh[0] || maskLoToHigh[1];
82   }
83 
84   constexpr bool operator==(const SanitizerMask &V) const {
85     return maskLoToHigh[0] == V.maskLoToHigh[0] &&
86            maskLoToHigh[1] == V.maskLoToHigh[1];
87   }
88 
89   SanitizerMask &operator&=(const SanitizerMask &RHS) {
90     for (unsigned k = 0; k < kNumElem; k++)
91       maskLoToHigh[k] &= RHS.maskLoToHigh[k];
92     return *this;
93   }
94 
95   SanitizerMask &operator|=(const SanitizerMask &RHS) {
96     for (unsigned k = 0; k < kNumElem; k++)
97       maskLoToHigh[k] |= RHS.maskLoToHigh[k];
98     return *this;
99   }
100 
101   constexpr bool operator!() const { return !bool(*this); }
102 
103   constexpr bool operator!=(const SanitizerMask &RHS) const {
104     return !((*this) == RHS);
105   }
106 
107   friend constexpr inline SanitizerMask operator~(SanitizerMask v) {
108     return SanitizerMask(~v.maskLoToHigh[0], ~v.maskLoToHigh[1]);
109   }
110 
111   friend constexpr inline SanitizerMask operator&(SanitizerMask a,
112                                                   const SanitizerMask &b) {
113     return SanitizerMask(a.maskLoToHigh[0] & b.maskLoToHigh[0],
114                          a.maskLoToHigh[1] & b.maskLoToHigh[1]);
115   }
116 
117   friend constexpr inline SanitizerMask operator|(SanitizerMask a,
118                                                   const SanitizerMask &b) {
119     return SanitizerMask(a.maskLoToHigh[0] | b.maskLoToHigh[0],
120                          a.maskLoToHigh[1] | b.maskLoToHigh[1]);
121   }
122 };
123 
124 // Declaring in clang namespace so that it can be found by ADL.
125 llvm::hash_code hash_value(const clang::SanitizerMask &Arg);
126 
127 // Define the set of sanitizer kinds, as well as the set of sanitizers each
128 // sanitizer group expands into.
129 struct SanitizerKind {
130   // Assign ordinals to possible values of -fsanitize= flag, which we will use
131   // as bit positions.
132   enum SanitizerOrdinal : uint64_t {
133 #define SANITIZER(NAME, ID) SO_##ID,
134 #define SANITIZER_GROUP(NAME, ID, ALIAS) SO_##ID##Group,
135 #include "clang/Basic/Sanitizers.def"
136     SO_Count
137   };
138 
139 #define SANITIZER(NAME, ID)                                                    \
140   static constexpr SanitizerMask ID = SanitizerMask::bitPosToMask(SO_##ID);    \
141   static_assert(SanitizerMask::checkBitPos(SO_##ID), "Bit position too big.");
142 #define SANITIZER_GROUP(NAME, ID, ALIAS)                                       \
143   static constexpr SanitizerMask ID = SanitizerMask(ALIAS);                    \
144   static constexpr SanitizerMask ID##Group =                                   \
145       SanitizerMask::bitPosToMask(SO_##ID##Group);                             \
146   static_assert(SanitizerMask::checkBitPos(SO_##ID##Group),                    \
147                 "Bit position too big.");
148 #include "clang/Basic/Sanitizers.def"
149 }; // SanitizerKind
150 
151 struct SanitizerSet {
152   /// Check if a certain (single) sanitizer is enabled.
153   bool has(SanitizerMask K) const {
154     assert(K.isPowerOf2() && "Has to be a single sanitizer.");
155     return static_cast<bool>(Mask & K);
156   }
157 
158   /// Check if one or more sanitizers are enabled.
159   bool hasOneOf(SanitizerMask K) const { return static_cast<bool>(Mask & K); }
160 
161   /// Enable or disable a certain (single) sanitizer.
162   void set(SanitizerMask K, bool Value) {
163     assert(K.isPowerOf2() && "Has to be a single sanitizer.");
164     Mask = Value ? (Mask | K) : (Mask & ~K);
165   }
166 
167   /// Disable the sanitizers specified in \p K.
168   void clear(SanitizerMask K = SanitizerKind::All) { Mask &= ~K; }
169 
170   /// Returns true if no sanitizers are enabled.
171   bool empty() const { return !Mask; }
172 
173   /// Bitmask of enabled sanitizers.
174   SanitizerMask Mask;
175 };
176 
177 /// Parse a single value from a -fsanitize= or -fno-sanitize= value list.
178 /// Returns a non-zero SanitizerMask, or \c 0 if \p Value is not known.
179 SanitizerMask parseSanitizerValue(StringRef Value, bool AllowGroups);
180 
181 /// For each sanitizer group bit set in \p Kinds, set the bits for sanitizers
182 /// this group enables.
183 SanitizerMask expandSanitizerGroups(SanitizerMask Kinds);
184 
185 /// Return the sanitizers which do not affect preprocessing.
186 inline SanitizerMask getPPTransparentSanitizers() {
187   return SanitizerKind::CFI | SanitizerKind::Integer |
188          SanitizerKind::ImplicitConversion | SanitizerKind::Nullability |
189          SanitizerKind::Undefined | SanitizerKind::FloatDivideByZero;
190 }
191 
192 } // namespace clang
193 
194 #endif // LLVM_CLANG_BASIC_SANITIZERS_H
195