/*

 * SPDX-License-Identifier: ISC

 *

 * Copyright 2023, Sergey Bronnikov.

 */

#include <assert.h>

#include <string.h>

#if defined(__cplusplus)

extern "C" {

#endif /* defined(__cplusplus) */

#include "lua.h"

#include "lualib.h"

#include "lauxlib.h"

#if defined(__cplusplus)

} /* extern "C" */

#endif /* defined(__cplusplus) */

#include <fuzzer/FuzzedDataProvider.h>

typedef struct {

  FuzzedDataProvider *fdp;

} dt;

static const char *

Reader(lua_State *L, void *data, size_t *size)

{

  dt *test_data = (dt *)data;

  static char *buf = NULL;

  FuzzedDataProvider *fdp = test_data->fdp;

  uint8_t max_str_size = fdp->ConsumeIntegral<uint8_t>();

  if (fdp->remaining_bytes() < max_str_size)

    return NULL;

  auto str = fdp->ConsumeRandomLengthString(max_str_size);

  *size = str.size();

  free(buf);

  buf = (char *)malloc(*size);

  assert(buf);

  memcpy(buf, str.c_str(), *size);

  return buf;

}

extern "C" int

LLVMFuzzerTestOneInput(const uint8_t *data, size_t size)

{

  lua_State *L = luaL_newstate();

  if (L == NULL)

    return 0;

  luaL_openlibs(L);

  FuzzedDataProvider fdp(data, size);

  dt test_data;

  test_data.fdp = &fdp;

  const char *mode = "t";

#if LUA_VERSION_NUM == 501

  int res = lua_load(L, Reader, &test_data, "libFuzzer");

#else /* Lua 5.3+ */

  int res = lua_load(L, Reader, &test_data, "libFuzzer", mode);

#endif /* LUA_VERSION_NUM */

  if (res == LUA_OK) {

    lua_pcall(L, 0, 0, 0);

  }

  lua_settop(L, 0);

  lua_close(L);

  return 0;

}