FuzzedDataProvider.h | Explore in Territory

//===- FuzzedDataProvider.h - Utility header for fuzz targets ---*- 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
//
//===----------------------------------------------------------------------===//
// A single header library providing an utility class to break up an array of
// bytes. Whenever run on the same input, provides the same output, as long as
// its methods are called in the same order, with the same arguments.
//===----------------------------------------------------------------------===//

#ifndef LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_
#define LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_

#include <algorithm>
#include <array>
#include <climits>
#include <cstddef>
#include <cstdint>
#include <cstring>
#include <initializer_list>
#include <limits>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>

// In addition to the comments below, the API is also briefly documented at
// https://github.com/google/fuzzing/blob/master/docs/split-inputs.md#fuzzed-data-provider
class FuzzedDataProvider { … };

// Returns a std::vector containing |num_bytes| of input data. If fewer than
// |num_bytes| of data remain, returns a shorter std::vector containing all
// of the data that's left. Can be used with any byte sized type, such as
// char, unsigned char, uint8_t, etc.
template <typename T>
std::vector<T> FuzzedDataProvider::ConsumeBytes(size_t num_bytes) { … }

// Similar to |ConsumeBytes|, but also appends the terminator value at the end
// of the resulting vector. Useful, when a mutable null-terminated C-string is
// needed, for example. But that is a rare case. Better avoid it, if possible,
// and prefer using |ConsumeBytes| or |ConsumeBytesAsString| methods.
template <typename T>
std::vector<T> FuzzedDataProvider::ConsumeBytesWithTerminator(size_t num_bytes,
                                                              T terminator) { … }

// Returns a std::vector containing all remaining bytes of the input data.
template <typename T>
std::vector<T> FuzzedDataProvider::ConsumeRemainingBytes() { … }

// Returns a std::string containing |num_bytes| of input data. Using this and
// |.c_str()| on the resulting string is the best way to get an immutable
// null-terminated C string. If fewer than |num_bytes| of data remain, returns
// a shorter std::string containing all of the data that's left.
inline std::string FuzzedDataProvider::ConsumeBytesAsString(size_t num_bytes) { … }

// Returns a std::string of length from 0 to |max_length|. When it runs out of
// input data, returns what remains of the input. Designed to be more stable
// with respect to a fuzzer inserting characters than just picking a random
// length and then consuming that many bytes with |ConsumeBytes|.
inline std::string
FuzzedDataProvider::ConsumeRandomLengthString(size_t max_length) { … }

// Returns a std::string of length from 0 to |remaining_bytes_|.
inline std::string FuzzedDataProvider::ConsumeRandomLengthString() { … }

// Returns a std::string containing all remaining bytes of the input data.
// Prefer using |ConsumeRemainingBytes| unless you actually need a std::string
// object.
inline std::string FuzzedDataProvider::ConsumeRemainingBytesAsString() { … }

// Returns a number in the range [Type's min, Type's max]. The value might
// not be uniformly distributed in the given range. If there's no input data
// left, always returns |min|.
template <typename T> T FuzzedDataProvider::ConsumeIntegral() { … }

// Returns a number in the range [min, max] by consuming bytes from the
// input data. The value might not be uniformly distributed in the given
// range. If there's no input data left, always returns |min|. |min| must
// be less than or equal to |max|.
template <typename T>
T FuzzedDataProvider::ConsumeIntegralInRange(T min, T max) { … }

// Returns a floating point value in the range [Type's lowest, Type's max] by
// consuming bytes from the input data. If there's no input data left, always
// returns approximately 0.
template <typename T> T FuzzedDataProvider::ConsumeFloatingPoint() { … }

// Returns a floating point value in the given range by consuming bytes from
// the input data. If there's no input data left, returns |min|. Note that
// |min| must be less than or equal to |max|.
template <typename T>
T FuzzedDataProvider::ConsumeFloatingPointInRange(T min, T max) { … }

// Returns a floating point number in the range [0.0, 1.0]. If there's no
// input data left, always returns 0.
template <typename T> T FuzzedDataProvider::ConsumeProbability() { … }

// Reads one byte and returns a bool, or false when no data remains.
inline bool FuzzedDataProvider::ConsumeBool() { … }

// Returns an enum value. The enum must start at 0 and be contiguous. It must
// also contain |kMaxValue| aliased to its largest (inclusive) value. Such as:
// enum class Foo { SomeValue, OtherValue, kMaxValue = OtherValue };
template <typename T> T FuzzedDataProvider::ConsumeEnum() { … }

// Returns a copy of the value selected from the given fixed-size |array|.
template <typename T, size_t size>
T FuzzedDataProvider::PickValueInArray(const T (&array)[size]) { … }

template <typename T, size_t size>
T FuzzedDataProvider::PickValueInArray(const std::array<T, size> &array) { … }

template <typename T>
T FuzzedDataProvider::PickValueInArray(std::initializer_list<const T> list) { … }

// Writes |num_bytes| of input data to the given destination pointer. If there
// is not enough data left, writes all remaining bytes. Return value is the
// number of bytes written.
// In general, it's better to avoid using this function, but it may be useful
// in cases when it's necessary to fill a certain buffer or object with
// fuzzing data.
inline size_t FuzzedDataProvider::ConsumeData(void *destination,
                                              size_t num_bytes) { … }

// Private methods.
inline void FuzzedDataProvider::CopyAndAdvance(void *destination,
                                               size_t num_bytes) { … }

inline void FuzzedDataProvider::Advance(size_t num_bytes) { … }

template <typename T>
std::vector<T> FuzzedDataProvider::ConsumeBytes(size_t size, size_t num_bytes) { … }

template <typename TS, typename TU>
TS FuzzedDataProvider::ConvertUnsignedToSigned(TU value) { … }

#endif // LLVM_FUZZER_FUZZED_DATA_PROVIDER_H_
chromium/third_party/llvm-build/Release+Asserts/lib/clang/20/include/fuzzer/FuzzedDataProvider.h
