xref: /llvm-project/compiler-rt/lib/fuzzer/FuzzerDictionary.h (revision bde4ffe7521421cfa891c7d6e526566920326b3f)
1 //===- FuzzerDictionary.h - Internal header for the Fuzzer ------*- 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 // fuzzer::Dictionary
9 //===----------------------------------------------------------------------===//
10 
11 #ifndef LLVM_FUZZER_DICTIONARY_H
12 #define LLVM_FUZZER_DICTIONARY_H
13 
14 #include "FuzzerDefs.h"
15 #include "FuzzerIO.h"
16 #include "FuzzerUtil.h"
17 #include <algorithm>
18 #include <limits>
19 
20 namespace fuzzer {
21 // A simple POD sized array of bytes.
22 template <size_t kMaxSizeT> class FixedWord {
23 public:
24   static const size_t kMaxSize = kMaxSizeT;
25   FixedWord() {}
26   FixedWord(const uint8_t *B, size_t S) { Set(B, S); }
27 
28   void Set(const uint8_t *B, size_t S) {
29     static_assert(kMaxSizeT <= std::numeric_limits<uint8_t>::max(),
30                   "FixedWord::kMaxSizeT cannot fit in a uint8_t.");
31     assert(S <= kMaxSize);
32     // memcpy cannot take null pointer arguments even if Size is 0.
33     if (S)
34       memcpy(Data, B, S);
35     Size = static_cast<uint8_t>(S);
36   }
37 
38   bool operator==(const FixedWord<kMaxSize> &w) const {
39     return Size == w.Size && 0 == memcmp(Data, w.Data, Size);
40   }
41 
42   static size_t GetMaxSize() { return kMaxSize; }
43   const uint8_t *data() const { return Data; }
44   uint8_t size() const { return Size; }
45 
46 private:
47   uint8_t Size = 0;
48   uint8_t Data[kMaxSize];
49 };
50 
51 typedef FixedWord<64> Word;
52 
53 class DictionaryEntry {
54  public:
55   DictionaryEntry() {}
56   DictionaryEntry(Word W) : W(W) {}
57   DictionaryEntry(Word W, size_t PositionHint)
58       : W(W), PositionHint(PositionHint) {}
59   const Word &GetW() const { return W; }
60 
61   bool HasPositionHint() const {
62     return PositionHint != std::numeric_limits<size_t>::max();
63   }
64   size_t GetPositionHint() const {
65     assert(HasPositionHint());
66     return PositionHint;
67   }
68   void IncUseCount() { UseCount++; }
69   void IncSuccessCount() { SuccessCount++; }
70   size_t GetUseCount() const { return UseCount; }
71   size_t GetSuccessCount() const {return SuccessCount; }
72 
73   void Print(const char *PrintAfter = "\n") {
74     PrintASCII(W.data(), W.size());
75     if (HasPositionHint())
76       Printf("@%zd", GetPositionHint());
77     Printf("%s", PrintAfter);
78   }
79 
80 private:
81   Word W;
82   size_t PositionHint = std::numeric_limits<size_t>::max();
83   size_t UseCount = 0;
84   size_t SuccessCount = 0;
85 };
86 
87 class Dictionary {
88  public:
89   static const size_t kMaxDictSize = 1 << 14;
90 
91   bool ContainsWord(const Word &W) const {
92     return std::any_of(begin(), end(), [&](const DictionaryEntry &DE) {
93       return DE.GetW() == W;
94     });
95   }
96   const DictionaryEntry *begin() const { return &DE[0]; }
97   const DictionaryEntry *end() const { return begin() + Size; }
98   DictionaryEntry & operator[] (size_t Idx) {
99     assert(Idx < Size);
100     return DE[Idx];
101   }
102   void push_back(DictionaryEntry DE) {
103     if (Size < kMaxDictSize)
104       this->DE[Size++] = DE;
105   }
106   void clear() { Size = 0; }
107   bool empty() const { return Size == 0; }
108   size_t size() const { return Size; }
109 
110 private:
111   DictionaryEntry DE[kMaxDictSize];
112   size_t Size = 0;
113 };
114 
115 // Parses one dictionary entry.
116 // If successful, writes the entry to Unit and returns true,
117 // otherwise returns false.
118 bool ParseOneDictionaryEntry(const std::string &Str, Unit *U);
119 // Parses the dictionary file, fills Units, returns true iff all lines
120 // were parsed successfully.
121 bool ParseDictionaryFile(const std::string &Text, std::vector<Unit> *Units);
122 
123 }  // namespace fuzzer
124 
125 #endif  // LLVM_FUZZER_DICTIONARY_H
126