lz4/ossfuzz/fuzz_helpers.h

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/*
* Copyright (c) 2016-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
*/
/**
* Helper functions for fuzzing.
*/
#ifndef FUZZ_HELPERS_H
#define FUZZ_HELPERS_H
#include "fuzz.h"
#include "xxhash.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef __cplusplus
extern "C" {
#endif
#define LZ4_COMMONDEFS_ONLY
#ifndef LZ4_SRC_INCLUDED
#include "lz4.c" /* LZ4_count, constants, mem */
#endif
#define MIN(a,b) ( (a) < (b) ? (a) : (b) )
#define MAX(a,b) ( (a) > (b) ? (a) : (b) )
#define FUZZ_QUOTE_IMPL(str) #str
#define FUZZ_QUOTE(str) FUZZ_QUOTE_IMPL(str)
/**
* Asserts for fuzzing that are always enabled.
*/
#define FUZZ_ASSERT_MSG(cond, msg) \
((cond) ? (void)0 \
: (fprintf(stderr, "%s: %u: Assertion: `%s' failed. %s\n", __FILE__, \
__LINE__, FUZZ_QUOTE(cond), (msg)), \
abort()))
#define FUZZ_ASSERT(cond) FUZZ_ASSERT_MSG((cond), "");
#if defined(__GNUC__)
#define FUZZ_STATIC static __inline __attribute__((unused))
#elif defined(__cplusplus) || \
(defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#define FUZZ_STATIC static inline
#elif defined(_MSC_VER)
#define FUZZ_STATIC static __inline
#else
#define FUZZ_STATIC static
#endif
/**
* Deterministically constructs a seed based on the fuzz input.
* Consumes up to the first FUZZ_RNG_SEED_SIZE bytes of the input.
*/
FUZZ_STATIC uint32_t FUZZ_seed(uint8_t const **src, size_t* size) {
uint8_t const *data = *src;
size_t const toHash = MIN(FUZZ_RNG_SEED_SIZE, *size);
*size -= toHash;
*src += toHash;
return XXH32(data, toHash, 0);
}
#define FUZZ_rotl32(x, r) (((x) << (r)) | ((x) >> (32 - (r))))
FUZZ_STATIC uint32_t FUZZ_rand(uint32_t *state) {
static const uint32_t prime1 = 2654435761U;
static const uint32_t prime2 = 2246822519U;
uint32_t rand32 = *state;
rand32 *= prime1;
rand32 += prime2;
rand32 = FUZZ_rotl32(rand32, 13);
*state = rand32;
return rand32 >> 5;
}
/* Returns a random numer in the range [min, max]. */
FUZZ_STATIC uint32_t FUZZ_rand32(uint32_t *state, uint32_t min, uint32_t max) {
uint32_t random = FUZZ_rand(state);
return min + (random % (max - min + 1));
}
#ifdef __cplusplus
}
#endif
#endif