1 //===- FuzzerValueBitMap.h - INTERNAL - Bit map -----------------*- 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 // ValueBitMap. 9 //===----------------------------------------------------------------------===// 10 11 #ifndef LLVM_FUZZER_VALUE_BIT_MAP_H 12 #define LLVM_FUZZER_VALUE_BIT_MAP_H 13 14 #include "FuzzerDefs.h" 15 16 namespace fuzzer { 17 18 // A bit map containing kMapSizeInWords bits. 19 struct ValueBitMap { 20 static const size_t kMapSizeInBits = 1 << 16; 21 static const size_t kMapPrimeMod = 65371; // Largest Prime < kMapSizeInBits; 22 static const size_t kBitsInWord = (sizeof(uintptr_t) * 8); 23 static const size_t kMapSizeInWords = kMapSizeInBits / kBitsInWord; 24 public: 25 26 // Clears all bits. 27 void Reset() { memset(Map, 0, sizeof(Map)); } 28 29 // Computes a hash function of Value and sets the corresponding bit. 30 // Returns true if the bit was changed from 0 to 1. 31 ATTRIBUTE_NO_SANITIZE_ALL 32 inline bool AddValue(uintptr_t Value) { 33 uintptr_t Idx = Value % kMapSizeInBits; 34 uintptr_t WordIdx = Idx / kBitsInWord; 35 uintptr_t BitIdx = Idx % kBitsInWord; 36 uintptr_t Old = Map[WordIdx]; 37 uintptr_t New = Old | (1ULL << BitIdx); 38 Map[WordIdx] = New; 39 return New != Old; 40 } 41 42 ATTRIBUTE_NO_SANITIZE_ALL 43 inline bool AddValueModPrime(uintptr_t Value) { 44 return AddValue(Value % kMapPrimeMod); 45 } 46 47 inline bool Get(uintptr_t Idx) { 48 assert(Idx < kMapSizeInBits); 49 uintptr_t WordIdx = Idx / kBitsInWord; 50 uintptr_t BitIdx = Idx % kBitsInWord; 51 return Map[WordIdx] & (1ULL << BitIdx); 52 } 53 54 size_t SizeInBits() const { return kMapSizeInBits; } 55 56 template <class Callback> 57 ATTRIBUTE_NO_SANITIZE_ALL 58 void ForEach(Callback CB) const { 59 for (size_t i = 0; i < kMapSizeInWords; i++) 60 if (uintptr_t M = Map[i]) 61 for (size_t j = 0; j < sizeof(M) * 8; j++) 62 if (M & ((uintptr_t)1 << j)) 63 CB(i * sizeof(M) * 8 + j); 64 } 65 66 private: 67 ATTRIBUTE_ALIGNED(512) uintptr_t Map[kMapSizeInWords]; 68 }; 69 70 } // namespace fuzzer 71 72 #endif // LLVM_FUZZER_VALUE_BIT_MAP_H 73