49 lines · c
1//===- FuzzerRandom.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-exception6//7//===----------------------------------------------------------------------===//8// fuzzer::Random9//===----------------------------------------------------------------------===//10 11#ifndef LLVM_FUZZER_RANDOM_H12#define LLVM_FUZZER_RANDOM_H13 14#include <cmath>15#include <random>16 17namespace fuzzer {18class Random : public std::minstd_rand {19 public:20 Random(unsigned int seed) : std::minstd_rand(seed) {}21 result_type operator()() { return this->std::minstd_rand::operator()(); }22 template <typename T>23 typename std::enable_if<std::is_integral<T>::value, T>::type Rand() {24 return static_cast<T>(this->operator()());25 }26 size_t RandBool() { return this->operator()() % 2; }27 size_t SkewTowardsLast(size_t n) {28 size_t T = this->operator()(n * n);29 size_t Res = static_cast<size_t>(sqrt(T));30 return Res;31 }32 template <typename T>33 typename std::enable_if<std::is_integral<T>::value, T>::type operator()(T n) {34 return n ? Rand<T>() % n : 0;35 }36 template <typename T>37 typename std::enable_if<std::is_integral<T>::value, T>::type38 operator()(T From, T To) {39 assert(From < To);40 auto RangeSize = static_cast<unsigned long long>(To) -41 static_cast<unsigned long long>(From) + 1;42 return static_cast<T>(this->operator()(RangeSize) + From);43 }44};45 46} // namespace fuzzer47 48#endif // LLVM_FUZZER_RANDOM_H49