SPIRV-Tools/test/fuzzers/random_generator.h

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// Copyright (c) 2021 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef TEST_FUZZERS_RANDOM_GENERATOR_H_
#define TEST_FUZZERS_RANDOM_GENERATOR_H_
#include <cstdint>
#include <random>
#include "source/spirv_target_env.h"
namespace spvtools {
namespace fuzzers {
/// Pseudo random generator utility class for fuzzing
class RandomGenerator {
public:
/// @brief Initializes the internal engine
/// @param seed - seed value passed to engine
explicit RandomGenerator(uint64_t seed);
/// @brief Initializes the internal engine
/// @param data - data to calculate the seed from
/// @param size - size of the data
explicit RandomGenerator(const uint8_t* data, size_t size);
~RandomGenerator() {}
/// Calculate a seed value based on a blob of data.
/// Currently hashes bytes near the front of the buffer, after skipping N
/// bytes.
/// @param data - pointer to data to base calculation off of, must be !nullptr
/// @param size - number of elements in |data|, must be > 0
static uint64_t CalculateSeed(const uint8_t* data, size_t size);
/// Get random valid target env.
spv_target_env GetTargetEnv();
/// Get uint32_t value from uniform distribution.
/// @param lower - lower bound of integer generated
/// @param upper - upper bound of integer generated
/// @returns i, where lower <= i < upper
uint32_t GetUInt32(uint32_t lower, uint32_t upper);
/// Get uint32_t value from uniform distribution.
/// @param bound - Upper bound of integer generated
/// @returns i, where 0 <= i < bound
uint32_t GetUInt32(uint32_t bound);
private:
std::mt19937_64 engine_;
}; // class RandomGenerator
} // namespace fuzzers
} // namespace spvtools
#endif // TEST_FUZZERS_RANDOM_GENERATOR_UTILS_H_