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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 01:47:29 +0000 |
commit | 0ebf5bdf043a27fd3dfb7f92e0cb63d88954c44d (patch) | |
tree | a31f07c9bcca9d56ce61e9a1ffd30ef350d513aa /tools/fuzzing/libfuzzer/FuzzerValueBitMap.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-37a0381f8351b370577b65028ba1f6563ae23fdf.tar.xz firefox-esr-37a0381f8351b370577b65028ba1f6563ae23fdf.zip |
Adding upstream version 115.8.0esr.upstream/115.8.0esr
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/fuzzing/libfuzzer/FuzzerValueBitMap.h')
-rw-r--r-- | tools/fuzzing/libfuzzer/FuzzerValueBitMap.h | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/tools/fuzzing/libfuzzer/FuzzerValueBitMap.h b/tools/fuzzing/libfuzzer/FuzzerValueBitMap.h new file mode 100644 index 0000000000..ddbfe200af --- /dev/null +++ b/tools/fuzzing/libfuzzer/FuzzerValueBitMap.h @@ -0,0 +1,73 @@ +//===- FuzzerValueBitMap.h - INTERNAL - Bit map -----------------*- C++ -* ===// +// +// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. +// See https://llvm.org/LICENSE.txt for license information. +// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception +// +//===----------------------------------------------------------------------===// +// ValueBitMap. +//===----------------------------------------------------------------------===// + +#ifndef LLVM_FUZZER_VALUE_BIT_MAP_H +#define LLVM_FUZZER_VALUE_BIT_MAP_H + +#include "FuzzerPlatform.h" +#include <cstdint> + +namespace fuzzer { + +// A bit map containing kMapSizeInWords bits. +struct ValueBitMap { + static const size_t kMapSizeInBits = 1 << 16; + static const size_t kMapPrimeMod = 65371; // Largest Prime < kMapSizeInBits; + static const size_t kBitsInWord = (sizeof(uintptr_t) * 8); + static const size_t kMapSizeInWords = kMapSizeInBits / kBitsInWord; + public: + + // Clears all bits. + void Reset() { memset(Map, 0, sizeof(Map)); } + + // Computes a hash function of Value and sets the corresponding bit. + // Returns true if the bit was changed from 0 to 1. + ATTRIBUTE_NO_SANITIZE_ALL + inline bool AddValue(uintptr_t Value) { + uintptr_t Idx = Value % kMapSizeInBits; + uintptr_t WordIdx = Idx / kBitsInWord; + uintptr_t BitIdx = Idx % kBitsInWord; + uintptr_t Old = Map[WordIdx]; + uintptr_t New = Old | (1ULL << BitIdx); + Map[WordIdx] = New; + return New != Old; + } + + ATTRIBUTE_NO_SANITIZE_ALL + inline bool AddValueModPrime(uintptr_t Value) { + return AddValue(Value % kMapPrimeMod); + } + + inline bool Get(uintptr_t Idx) { + assert(Idx < kMapSizeInBits); + uintptr_t WordIdx = Idx / kBitsInWord; + uintptr_t BitIdx = Idx % kBitsInWord; + return Map[WordIdx] & (1ULL << BitIdx); + } + + size_t SizeInBits() const { return kMapSizeInBits; } + + template <class Callback> + ATTRIBUTE_NO_SANITIZE_ALL + void ForEach(Callback CB) const { + for (size_t i = 0; i < kMapSizeInWords; i++) + if (uintptr_t M = Map[i]) + for (size_t j = 0; j < sizeof(M) * 8; j++) + if (M & ((uintptr_t)1 << j)) + CB(i * sizeof(M) * 8 + j); + } + + private: + ATTRIBUTE_ALIGNED(512) uintptr_t Map[kMapSizeInWords]; +}; + +} // namespace fuzzer + +#endif // LLVM_FUZZER_VALUE_BIT_MAP_H |