zstd/tests/fuzz/fuzz_helpers.h
2017-07-03 12:40:12 -07:00

71 lines
2.1 KiB
C

/**
* Copyright (c) 2016-present, Facebook, Inc.
* All rights reserved.
*
* This source code is licensed under the BSD-style license found in the
* LICENSE file in the root directory of this source tree. An additional grant
* of patent rights can be found in the PATENTS file in the same directory.
*/
/**
* Helper functions for fuzzing.
*/
#ifndef FUZZ_HELPERS_H
#define FUZZ_HELPERS_H
#include "fuzz.h"
#include "xxhash.h"
#include <stdint.h>
#include <stdio.h>
#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
/**
* Determininistically constructs a seed based on the fuzz input.
* Only looks at the first FUZZ_RNG_SEED_SIZE bytes of the input.
*/
FUZZ_STATIC uint32_t FUZZ_seed(const uint8_t *src, size_t size) {
size_t const toHash = MIN(FUZZ_RNG_SEED_SIZE, size);
return XXH32(src, 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;
}
#endif