Limit memory usage for sqlite3 fuzzer + move it to sqlite dir.

testing/libfuzzer/fuzzers/sqlite3_prepare_v2_fuzzer.cc

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <algorithm>
-#include <array>
-#include <string>
-#include <vector>
-
-#include "third_party/sqlite/sqlite3.h"
-
-
-static const std::array<uint8_t, 6> kBadKeyword{{'R', 'E', 'G', 'E', 'X', 'P'}};
-
-
-bool checkForBadKeyword(const uint8_t* data, size_t size) {
-  auto it = std::search(
-      data, data + size, kBadKeyword.begin(), kBadKeyword.end(),
-      [](char c1, char c2) { return std::toupper(c1) == std::toupper(c2); });
-
-  if (it != data + size)
-    return true;
-
-  return false;
-}
-
-
-static int Progress(void *not_used_ptr) {
-  return 1;
-}
-
-
-// Entry point for LibFuzzer.
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  if (size < 2)
-    return 0;
-
-  if (checkForBadKeyword(data, size))
-    return 0;
-
-  sqlite3* db;
-  int return_code = sqlite3_open_v2(
-      "db.db",
-      &db,
-      SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE | SQLITE_OPEN_MEMORY, 0);
-
-
-  if (SQLITE_OK != return_code)
-    return 0;
-
-  // Use first byte as random selector for other parameters.
-  int selector = data[0];
-
-  // To cover both cases when progress_handler is used and isn't used.
-  if (selector & 1)
-    sqlite3_progress_handler(db, 4, &Progress, NULL);
-  else
-    sqlite3_progress_handler(db, 0, NULL, NULL);
-
-  // Remove least significant bit to make further usage of selector independent.
-  selector >>= 1;
-
-  sqlite3_stmt* statement = NULL;
-  int result = sqlite3_prepare_v2(db, reinterpret_cast<const char*>(data + 1),
-                                  static_cast<int>(size - 1), &statement, NULL);
-  if (result == SQLITE_OK) {
-    // Use selector value to randomize number of iterations.
-    for (int i = 0; i < selector; i++) {
-      if (sqlite3_step(statement) != SQLITE_ROW)
-        break;
-    }
-
-    sqlite3_finalize(statement);
-  }
-
-  sqlite3_close(db);
-  return 0;
-}