1 // Copyright (c) 2021 Google Inc. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #ifndef TEST_FUZZERS_RANDOM_GENERATOR_H_ 16 #define TEST_FUZZERS_RANDOM_GENERATOR_H_ 17 18 #include <cstdint> 19 #include <random> 20 21 #include "source/spirv_target_env.h" 22 23 namespace spvtools { 24 namespace fuzzers { 25 26 /// Pseudo random generator utility class for fuzzing 27 class RandomGenerator { 28 public: 29 /// @brief Initializes the internal engine 30 /// @param seed - seed value passed to engine 31 explicit RandomGenerator(uint64_t seed); 32 33 /// @brief Initializes the internal engine 34 /// @param data - data to calculate the seed from 35 /// @param size - size of the data 36 explicit RandomGenerator(const uint8_t* data, size_t size); 37 ~RandomGenerator()38 ~RandomGenerator() {} 39 40 /// Calculate a seed value based on a blob of data. 41 /// Currently hashes bytes near the front of the buffer, after skipping N 42 /// bytes. 43 /// @param data - pointer to data to base calculation off of, must be !nullptr 44 /// @param size - number of elements in |data|, must be > 0 45 static uint64_t CalculateSeed(const uint8_t* data, size_t size); 46 47 /// Get random valid target env. 48 spv_target_env GetTargetEnv(); 49 50 /// Get uint32_t value from uniform distribution. 51 /// @param lower - lower bound of integer generated 52 /// @param upper - upper bound of integer generated 53 /// @returns i, where lower <= i < upper 54 uint32_t GetUInt32(uint32_t lower, uint32_t upper); 55 56 /// Get uint32_t value from uniform distribution. 57 /// @param bound - Upper bound of integer generated 58 /// @returns i, where 0 <= i < bound 59 uint32_t GetUInt32(uint32_t bound); 60 61 private: 62 std::mt19937_64 engine_; 63 }; // class RandomGenerator 64 65 } // namespace fuzzers 66 } // namespace spvtools 67 68 #endif // TEST_FUZZERS_RANDOM_GENERATOR_UTILS_H_ 69