[fuzz] Move from fuzz/ to tests/fuzz/

tests/fuzz/fuzz_helpers.h

@@ -0,0 +1,70 @@
+/**
+ * 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