gecko-dev/tools/fuzzing/common/FuzzingTraits.h

104 строки
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C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_fuzzing_FuzzingTraits_h
#define mozilla_fuzzing_FuzzingTraits_h
#include "mozilla/Assertions.h"
#include "mozilla/TypeTraits.h"
#include <random>
namespace mozilla {
namespace fuzzing {
/**
* RandomNumericLimit returns either the min or max limit of an arithmetic
* data type.
*/
template <typename T>
T RandomNumericLimit()
{
static_assert(mozilla::IsArithmetic<T>::value == true,
"T must be an arithmetic type");
return random() % 2 == 0 ? std::numeric_limits<T>::min()
: std::numeric_limits<T>::max();
}
/**
* RandomInteger generates negative and positive integers in 2**n increments.
*/
template <typename T>
T RandomInteger()
{
static_assert(mozilla::IsIntegral<T>::value == true,
"T must be an integral type");
double r = static_cast<double>(random() % ((sizeof(T) * CHAR_BIT) + 1));
T x = static_cast<T>(pow(2.0, r)) - 1;
if (std::numeric_limits<T>::is_signed && random() % 2 == 0) {
return (x * -1) - 1;
}
return x;
}
/**
* RandomIntegerRange returns a random integral within a [min, max] range.
*/
template <typename T>
T RandomIntegerRange(T min, T max)
{
static_assert(mozilla::IsIntegral<T>::value == true,
"T must be an integral type");
MOZ_ASSERT(min < max);
return static_cast<T>(random() % (max - min) + min);
}
/**
* RandomFloatingPointRange returns a random floating-point number within a
* [min, max] range.
*/
template <typename T>
T RandomFloatingPointRange(T min, T max)
{
static_assert(mozilla::IsFloatingPoint<T>::value == true,
"T must be a floating point type");
MOZ_ASSERT(min < max);
T x = static_cast<T>(random()) / static_cast<T>(RAND_MAX);
return min + x * (max - min);
}
/**
* RandomFloatingPoint returns a random floating-point number in 2**n
* increments.
*/
template <typename T>
T RandomFloatingPoint()
{
static_assert(mozilla::IsFloatingPoint<T>::value == true,
"T must be a floating point type");
int radix = RandomIntegerRange<int>(std::numeric_limits<T>::min_exponent,
std::numeric_limits<T>::max_exponent);
T x = static_cast<T>(pow(2.0, static_cast<double>(radix)));
return x * RandomFloatingPointRange<T>(-1.0, 1.0);
}
class FuzzingTraits
{
public:
static unsigned int Random(unsigned int aMax);
static bool Sometimes(unsigned int aProbability);
/**
* Frequency() defines how many mutations of a kind shall be applied to a
* target buffer by using a user definable factor. The higher the factor,
* the less mutations are being made.
*/
static size_t Frequency(const size_t aSize, const uint64_t aFactor);
};
} // namespace fuzzing
} // namespace mozilla
#endif