trezor-firmware/core/embed/unix/main.c

/*
 * This file is part of the MicroPython project, http://micropython.org/
 *
 * The MIT License (MIT)
 *
 * Copyright (c) 2013, 2014 Damien P. George
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include "extmod/misc.h"
#include "genhdr/mpversion.h"
#include "input.h"
#include "py/builtin.h"
#include "py/compile.h"
#include "py/gc.h"
#include "py/mphal.h"
#include "py/mpthread.h"
#include "py/repl.h"
#include "py/runtime.h"
#include "py/stackctrl.h"

#include "common.h"

// Command line options, with their defaults
STATIC bool compile_only = false;
STATIC uint emit_opt = MP_EMIT_OPT_NONE;

#if MICROPY_ENABLE_GC
// Heap size of GC heap (if enabled)
// Make it larger on a 64 bit machine, because pointers are larger.
long heap_size = 1024 * 1024 * (sizeof(mp_uint_t) / 4);
#endif

STATIC void stderr_print_strn(void *env, const char *str, size_t len) {
  (void)env;
  ssize_t dummy = write(STDERR_FILENO, str, len);
  mp_uos_dupterm_tx_strn(str, len);
  (void)dummy;
}

const mp_print_t mp_stderr_print = {NULL, stderr_print_strn};

#define FORCED_EXIT (0x100)
// If exc is SystemExit, return value where FORCED_EXIT bit set,
// and lower 8 bits are SystemExit value. For all other exceptions,
// return 1.
STATIC int handle_uncaught_exception(mp_obj_base_t *exc) {
  // check for SystemExit
  if (mp_obj_is_subclass_fast(MP_OBJ_FROM_PTR(exc->type),
                              MP_OBJ_FROM_PTR(&mp_type_SystemExit))) {
    // None is an exit value of 0; an int is its value; anything else is 1
    mp_obj_t exit_val = mp_obj_exception_get_value(MP_OBJ_FROM_PTR(exc));
    mp_int_t val = 0;
    if (exit_val != mp_const_none && !mp_obj_get_int_maybe(exit_val, &val)) {
      val = 1;
    }
    return FORCED_EXIT | (val & 255);
  }

  // Report all other exceptions
  mp_obj_print_exception(&mp_stderr_print, MP_OBJ_FROM_PTR(exc));
  return 1;
}

#define LEX_SRC_STR (1)
#define LEX_SRC_VSTR (2)
#define LEX_SRC_FILENAME (3)
#define LEX_SRC_STDIN (4)

// Returns standard error codes: 0 for success, 1 for all other errors,
// except if FORCED_EXIT bit is set then script raised SystemExit and the
// value of the exit is in the lower 8 bits of the return value
STATIC int execute_from_lexer(int source_kind, const void *source,
                              mp_parse_input_kind_t input_kind, bool is_repl) {
  mp_hal_set_interrupt_char(CHAR_CTRL_C);

  nlr_buf_t nlr;
  if (nlr_push(&nlr) == 0) {
    // create lexer based on source kind
    mp_lexer_t *lex;
    if (source_kind == LEX_SRC_STR) {
      const char *line = source;
      lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, line, strlen(line),
                                      false);
    } else if (source_kind == LEX_SRC_VSTR) {
      const vstr_t *vstr = source;
      lex = mp_lexer_new_from_str_len(MP_QSTR__lt_stdin_gt_, vstr->buf,
                                      vstr->len, false);
    } else if (source_kind == LEX_SRC_FILENAME) {
      lex = mp_lexer_new_from_file((const char *)source);
    } else {  // LEX_SRC_STDIN
      lex = mp_lexer_new_from_fd(MP_QSTR__lt_stdin_gt_, 0, false);
    }

    qstr source_name = lex->source_name;

#if MICROPY_PY___FILE__
    if (input_kind == MP_PARSE_FILE_INPUT) {
      mp_store_global(MP_QSTR___file__, MP_OBJ_NEW_QSTR(source_name));
    }
#endif

    mp_parse_tree_t parse_tree = mp_parse(lex, input_kind);

#if defined(MICROPY_UNIX_COVERAGE)
    // allow to print the parse tree in the coverage build
    if (mp_verbose_flag >= 3) {
      printf("----------------\n");
      mp_parse_node_print(parse_tree.root, 0);
      printf("----------------\n");
    }
#endif

    mp_obj_t module_fun = mp_compile(&parse_tree, source_name, is_repl);

    if (!compile_only) {
      // execute it
      mp_call_function_0(module_fun);
      // check for pending exception
      if (MP_STATE_VM(mp_pending_exception) != MP_OBJ_NULL) {
        mp_obj_t obj = MP_STATE_VM(mp_pending_exception);
        MP_STATE_VM(mp_pending_exception) = MP_OBJ_NULL;
        nlr_raise(obj);
      }
    }

    mp_hal_set_interrupt_char(-1);
    nlr_pop();
    return 0;

  } else {
    // uncaught exception
    mp_hal_set_interrupt_char(-1);
    return handle_uncaught_exception(nlr.ret_val);
  }
}

#if MICROPY_USE_READLINE == 1
#include "lib/mp-readline/readline.h"
#else
STATIC char *strjoin(const char *s1, int sep_char, const char *s2) {
  int l1 = strlen(s1);
  int l2 = strlen(s2);
  char *s = malloc(l1 + l2 + 2);
  memcpy(s, s1, l1);
  if (sep_char != 0) {
    s[l1] = sep_char;
    l1 += 1;
  }
  memcpy(s + l1, s2, l2);
  s[l1 + l2] = 0;
  return s;
}
#endif

STATIC int do_repl(void) {
  mp_hal_stdout_tx_str("MicroPython " MICROPY_GIT_TAG " on " MICROPY_BUILD_DATE
                       "; " MICROPY_PY_SYS_PLATFORM
                       " version\nUse Ctrl-D to exit, Ctrl-E for paste mode\n");

#if MICROPY_USE_READLINE == 1

  // use MicroPython supplied readline

  vstr_t line;
  vstr_init(&line, 16);
  for (;;) {
    mp_hal_stdio_mode_raw();

  input_restart:
    vstr_reset(&line);
    int ret = readline(&line, ">>> ");
    mp_parse_input_kind_t parse_input_kind = MP_PARSE_SINGLE_INPUT;

    if (ret == CHAR_CTRL_C) {
      // cancel input
      mp_hal_stdout_tx_str("\r\n");
      goto input_restart;
    } else if (ret == CHAR_CTRL_D) {
      // EOF
      printf("\n");
      mp_hal_stdio_mode_orig();
      vstr_clear(&line);
      return 0;
    } else if (ret == CHAR_CTRL_E) {
      // paste mode
      mp_hal_stdout_tx_str(
          "\npaste mode; Ctrl-C to cancel, Ctrl-D to finish\n=== ");
      vstr_reset(&line);
      for (;;) {
        char c = mp_hal_stdin_rx_chr();
        if (c == CHAR_CTRL_C) {
          // cancel everything
          mp_hal_stdout_tx_str("\n");
          goto input_restart;
        } else if (c == CHAR_CTRL_D) {
          // end of input
          mp_hal_stdout_tx_str("\n");
          break;
        } else {
          // add char to buffer and echo
          vstr_add_byte(&line, c);
          if (c == '\r') {
            mp_hal_stdout_tx_str("\n=== ");
          } else {
            mp_hal_stdout_tx_strn(&c, 1);
          }
        }
      }
      parse_input_kind = MP_PARSE_FILE_INPUT;
    } else if (line.len == 0) {
      if (ret != 0) {
        printf("\n");
      }
      goto input_restart;
    } else {
      // got a line with non-zero length, see if it needs continuing
      while (mp_repl_continue_with_input(vstr_null_terminated_str(&line))) {
        vstr_add_byte(&line, '\n');
        ret = readline(&line, "... ");
        if (ret == CHAR_CTRL_C) {
          // cancel everything
          printf("\n");
          goto input_restart;
        } else if (ret == CHAR_CTRL_D) {
          // stop entering compound statement
          break;
        }
      }
    }

    mp_hal_stdio_mode_orig();

    ret = execute_from_lexer(LEX_SRC_VSTR, &line, parse_input_kind, true);
    if (ret & FORCED_EXIT) {
      return ret;
    }
  }

#else

  // use simple readline

  for (;;) {
    char *line = prompt(">>> ");
    if (line == NULL) {
      // EOF
      return 0;
    }
    while (mp_repl_continue_with_input(line)) {
      char *line2 = prompt("... ");
      if (line2 == NULL) {
        break;
      }
      char *line3 = strjoin(line, '\n', line2);
      free(line);
      free(line2);
      line = line3;
    }

    int ret =
        execute_from_lexer(LEX_SRC_STR, line, MP_PARSE_SINGLE_INPUT, true);
    if (ret & FORCED_EXIT) {
      return ret;
    }
    free(line);
  }

#endif
}

STATIC int do_file(const char *file) {
  return execute_from_lexer(LEX_SRC_FILENAME, file, MP_PARSE_FILE_INPUT, false);
}

STATIC int do_str(const char *str) {
  return execute_from_lexer(LEX_SRC_STR, str, MP_PARSE_FILE_INPUT, false);
}

STATIC int usage(char **argv) {
  printf(
      "usage: %s [<opts>] [-X <implopt>] [-c <command>] [<filename>]\n"
      "Options:\n"
      "-v : verbose (trace various operations); can be multiple\n"
      "-O[N] : apply bytecode optimizations of level N\n"
      "\n"
      "Implementation specific options (-X):\n",
      argv[0]);
  int impl_opts_cnt = 0;
  printf(
      "  compile-only                 -- parse and compile only\n"
#if MICROPY_EMIT_NATIVE
      "  emit={bytecode,native,viper} -- set the default code emitter\n"
#else
      "  emit=bytecode                -- set the default code emitter\n"
#endif
  );
  impl_opts_cnt++;
#if MICROPY_ENABLE_GC
  printf(
      "  heapsize=<n>[w][K|M] -- set the heap size for the GC (default %ld)\n",
      heap_size);
  impl_opts_cnt++;
#endif

  if (impl_opts_cnt == 0) {
    printf("  (none)\n");
  }

  return 1;
}

// Process options which set interpreter init options
STATIC void pre_process_options(int argc, char **argv) {
  for (int a = 1; a < argc; a++) {
    if (argv[a][0] == '-') {
      if (strcmp(argv[a], "-X") == 0) {
        if (a + 1 >= argc) {
          exit(usage(argv));
        }
        if (0) {
        } else if (strcmp(argv[a + 1], "compile-only") == 0) {
          compile_only = true;
        } else if (strcmp(argv[a + 1], "emit=bytecode") == 0) {
          emit_opt = MP_EMIT_OPT_BYTECODE;
#if MICROPY_EMIT_NATIVE
        } else if (strcmp(argv[a + 1], "emit=native") == 0) {
          emit_opt = MP_EMIT_OPT_NATIVE_PYTHON;
        } else if (strcmp(argv[a + 1], "emit=viper") == 0) {
          emit_opt = MP_EMIT_OPT_VIPER;
#endif
#if MICROPY_ENABLE_GC
        } else if (strncmp(argv[a + 1], "heapsize=", sizeof("heapsize=") - 1) ==
                   0) {
          char *end;
          heap_size = strtol(argv[a + 1] + sizeof("heapsize=") - 1, &end, 0);
          // Don't bring unneeded libc dependencies like tolower()
          // If there's 'w' immediately after number, adjust it for
          // target word size. Note that it should be *before* size
          // suffix like K or M, to avoid confusion with kilowords,
          // etc. the size is still in bytes, just can be adjusted
          // for word size (taking 32bit as baseline).
          bool word_adjust = false;
          if ((*end | 0x20) == 'w') {
            word_adjust = true;
            end++;
          }
          if ((*end | 0x20) == 'k') {
            heap_size *= 1024;
          } else if ((*end | 0x20) == 'm') {
            heap_size *= 1024 * 1024;
          } else {
            // Compensate for ++ below
            --end;
          }
          if (*++end != 0) {
            goto invalid_arg;
          }
          if (word_adjust) {
            heap_size = heap_size * BYTES_PER_WORD / 4;
          }
          // If requested size too small, we'll crash anyway
          if (heap_size < 700) {
            goto invalid_arg;
          }
#endif
        } else {
        invalid_arg:
          printf("Invalid option\n");
          exit(usage(argv));
        }
        a++;
      }
    }
  }
}

STATIC void set_sys_argv(char *argv[], int argc, int start_arg) {
  for (int i = start_arg; i < argc; i++) {
    mp_obj_list_append(mp_sys_argv, MP_OBJ_NEW_QSTR(qstr_from_str(argv[i])));
  }
}

void main_clean_exit(int status) {
  fflush(stdout);
  fflush(stderr);
  // sys.exit is disabled, so raise a SystemExit exception directly
  nlr_raise(mp_obj_new_exception_arg1(&mp_type_SystemExit,
                                      MP_OBJ_NEW_SMALL_INT(status)));
  // the above shouldn't return, but make sure we exit just in case
  exit(status);
}

#ifdef _WIN32
#define PATHLIST_SEP_CHAR ';'
#else
#define PATHLIST_SEP_CHAR ':'
#endif

MP_NOINLINE int main_(int argc, char **argv);

int main(int argc, char **argv) {
  collect_hw_entropy();

#if MICROPY_PY_THREAD
  mp_thread_init();
#endif
  // We should capture stack top ASAP after start, and it should be
  // captured guaranteedly before any other stack variables are allocated.
  // For this, actual main (renamed main_) should not be inlined into
  // this function. main_() itself may have other functions inlined (with
  // their own stack variables), that's why we need this main/main_ split.
  mp_stack_ctrl_init();
  return main_(argc, argv);
}

MP_NOINLINE int main_(int argc, char **argv) {
#ifdef SIGPIPE
  // Do not raise SIGPIPE, instead return EPIPE. Otherwise, e.g. writing
  // to peer-closed socket will lead to sudden termination of MicroPython
  // process. SIGPIPE is particularly nasty, because unix shell doesn't
  // print anything for it, so the above looks like completely sudden and
  // silent termination for unknown reason. Ignoring SIGPIPE is also what
  // CPython does. Note that this may lead to problems using MicroPython
  // scripts as pipe filters, but again, that's what CPython does. So,
  // scripts which want to follow unix shell pipe semantics (where SIGPIPE
  // means "pipe was requested to terminate, it's not an error"), should
  // catch EPIPE themselves.
  signal(SIGPIPE, SIG_IGN);
#endif

  mp_stack_set_limit(600000 * (BYTES_PER_WORD / 4));

  pre_process_options(argc, argv);

#if MICROPY_ENABLE_GC
  char *heap = malloc(heap_size);
  gc_init(heap, heap + heap_size);
#endif

#if MICROPY_ENABLE_PYSTACK
  static mp_obj_t pystack[1024];
  mp_pystack_init(pystack, &pystack[MP_ARRAY_SIZE(pystack)]);
#endif

  mp_init();

  char *home = getenv("HOME");
  char *path = getenv("MICROPYPATH");
  if (path == NULL) {
#ifdef MICROPY_PY_SYS_PATH_DEFAULT
    path = MICROPY_PY_SYS_PATH_DEFAULT;
#else
    path = "~/.micropython/lib:/usr/lib/micropython";
#endif
  }
  size_t path_num = 1;  // [0] is for current dir (or base dir of the script)
  if (*path == ':') {
    path_num++;
  }
  for (char *p = path; p != NULL; p = strchr(p, PATHLIST_SEP_CHAR)) {
    path_num++;
    if (p != NULL) {
      p++;
    }
  }
  mp_obj_list_init(MP_OBJ_TO_PTR(mp_sys_path), path_num);
  mp_obj_t *path_items;
  mp_obj_list_get(mp_sys_path, &path_num, &path_items);
  path_items[0] = MP_OBJ_NEW_QSTR(MP_QSTR_);
  {
    char *p = path;
    for (mp_uint_t i = 1; i < path_num; i++) {
      char *p1 = strchr(p, PATHLIST_SEP_CHAR);
      if (p1 == NULL) {
        p1 = p + strlen(p);
      }
      if (p[0] == '~' && p[1] == '/' && home != NULL) {
        // Expand standalone ~ to $HOME
        int home_l = strlen(home);
        vstr_t vstr;
        vstr_init(&vstr, home_l + (p1 - p - 1) + 1);
        vstr_add_strn(&vstr, home, home_l);
        vstr_add_strn(&vstr, p + 1, p1 - p - 1);
        path_items[i] = mp_obj_new_str_from_vstr(&mp_type_str, &vstr);
      } else {
        path_items[i] = mp_obj_new_str_via_qstr(p, p1 - p);
      }
      p = p1 + 1;
    }
  }

  mp_obj_list_init(MP_OBJ_TO_PTR(mp_sys_argv), 0);

#if defined(MICROPY_UNIX_COVERAGE)
  {
    MP_DECLARE_CONST_FUN_OBJ_0(extra_coverage_obj);
    mp_store_global(QSTR_FROM_STR_STATIC("extra_coverage"),
                    MP_OBJ_FROM_PTR(&extra_coverage_obj));
  }
#endif

  // Here is some example code to create a class and instance of that class.
  // First is the Python, then the C code.
  //
  // class TestClass:
  //     pass
  // test_obj = TestClass()
  // test_obj.attr = 42
  //
  // mp_obj_t test_class_type, test_class_instance;
  // test_class_type = mp_obj_new_type(QSTR_FROM_STR_STATIC("TestClass"),
  // mp_const_empty_tuple, mp_obj_new_dict(0));
  // mp_store_name(QSTR_FROM_STR_STATIC("test_obj"), test_class_instance =
  // mp_call_function_0(test_class_type)); mp_store_attr(test_class_instance,
  // QSTR_FROM_STR_STATIC("attr"), mp_obj_new_int(42));

  /*
  printf("bytes:\n");
  printf("    total %d\n", m_get_total_bytes_allocated());
  printf("    cur   %d\n", m_get_current_bytes_allocated());
  printf("    peak  %d\n", m_get_peak_bytes_allocated());
  */

  const int NOTHING_EXECUTED = -2;
  int ret = NOTHING_EXECUTED;
  bool inspect = false;
  for (int a = 1; a < argc; a++) {
    if (argv[a][0] == '-') {
      if (strcmp(argv[a], "-i") == 0) {
        inspect = true;
      } else if (strcmp(argv[a], "-c") == 0) {
        if (a + 1 >= argc) {
          return usage(argv);
        }
        ret = do_str(argv[a + 1]);
        if (ret & FORCED_EXIT) {
          break;
        }
        a += 1;
      } else if (strcmp(argv[a], "-m") == 0) {
        if (a + 1 >= argc) {
          return usage(argv);
        }
        mp_obj_t import_args[4];
        import_args[0] = mp_obj_new_str(argv[a + 1], strlen(argv[a + 1]));
        import_args[1] = import_args[2] = mp_const_none;
        // Ask __import__ to handle imported module specially - set its __name__
        // to __main__, and also return this leaf module, not top-level package
        // containing it.
        import_args[3] = mp_const_false;
        // TODO: https://docs.python.org/3/using/cmdline.html#cmdoption-m :
        // "the first element of sys.argv will be the full path to
        // the module file (while the module file is being located,
        // the first element will be set to "-m")."
        set_sys_argv(argv, argc, a + 1);

        mp_obj_t mod;
        nlr_buf_t nlr;
        bool subpkg_tried = false;

      reimport:
        if (nlr_push(&nlr) == 0) {
          mod = mp_builtin___import__(MP_ARRAY_SIZE(import_args), import_args);
          nlr_pop();
        } else {
          // uncaught exception
          return handle_uncaught_exception(nlr.ret_val) & 0xff;
        }

        if (mp_obj_is_package(mod) && !subpkg_tried) {
          subpkg_tried = true;
          vstr_t vstr;
          int len = strlen(argv[a + 1]);
          vstr_init(&vstr, len + sizeof(".__main__"));
          vstr_add_strn(&vstr, argv[a + 1], len);
          vstr_add_strn(&vstr, ".__main__", sizeof(".__main__") - 1);
          import_args[0] = mp_obj_new_str_from_vstr(&mp_type_str, &vstr);
          goto reimport;
        }

        ret = 0;
        break;
      } else if (strcmp(argv[a], "-X") == 0) {
        a += 1;
#if MICROPY_DEBUG_PRINTERS
      } else if (strcmp(argv[a], "-v") == 0) {
        mp_verbose_flag++;
#endif
      } else if (strncmp(argv[a], "-O", 2) == 0) {
        if (unichar_isdigit(argv[a][2])) {
          MP_STATE_VM(mp_optimise_value) = argv[a][2] & 0xf;
        } else {
          MP_STATE_VM(mp_optimise_value) = 0;
          for (char *p = argv[a] + 1; *p && *p == 'O';
               p++, MP_STATE_VM(mp_optimise_value)++)
            ;
        }
      } else {
        return usage(argv);
      }
    } else {
      char *pathbuf = malloc(PATH_MAX);
      char *basedir = realpath(argv[a], pathbuf);
      if (basedir == NULL) {
        mp_printf(&mp_stderr_print, "%s: can't open file '%s': [Errno %d] %s\n",
                  argv[0], argv[a], errno, strerror(errno));
        // CPython exits with 2 in such case
        ret = 2;
        break;
      }

      // Set base dir of the script as first entry in sys.path
      char *p = strrchr(basedir, '/');
      path_items[0] = mp_obj_new_str_via_qstr(basedir, p - basedir);
      free(pathbuf);

      set_sys_argv(argv, argc, a);
      ret = do_file(argv[a]);
      break;
    }
  }

  if (ret == NOTHING_EXECUTED || inspect) {
    if (isatty(0)) {
      prompt_read_history();
      ret = do_repl();
      prompt_write_history();
    } else {
      ret = execute_from_lexer(LEX_SRC_STDIN, NULL, MP_PARSE_FILE_INPUT, false);
    }
  }

#if MICROPY_PY_SYS_SETTRACE
  MP_STATE_THREAD(prof_trace_callback) = MP_OBJ_NULL;
#endif

#if MICROPY_PY_SYS_ATEXIT
  // Beware, the sys.settrace callback should be disabled before running
  // sys.atexit.
  if (mp_obj_is_callable(MP_STATE_VM(sys_exitfunc))) {
    mp_call_function_0(MP_STATE_VM(sys_exitfunc));
  }
#endif

#if MICROPY_PY_MICROPYTHON_MEM_INFO
  char *env_str_trezor_log_memory = getenv("TREZOR_LOG_MEMORY");
  if (!env_str_trezor_log_memory || atoi(env_str_trezor_log_memory) == 0) {
    env_str_trezor_log_memory = NULL;
  }
  if (mp_verbose_flag || env_str_trezor_log_memory) {
    mp_micropython_mem_info(0, NULL);
  }
#endif

  mp_deinit();

#if MICROPY_ENABLE_GC && !defined(NDEBUG)
  // We don't really need to free memory since we are about to exit the
  // process, but doing so helps to find memory leaks.
  free(heap);
#endif

  // printf("total bytes = %d\n", m_get_total_bytes_allocated());
  return ret & 0xff;
}

#ifdef TREZOR_EMULATOR_FROZEN
uint mp_import_stat(const char *path) { return MP_IMPORT_STAT_NO_EXIST; }
#else
uint mp_import_stat(const char *path) {
  struct stat st;
  if (stat(path, &st) == 0) {
    if (S_ISDIR(st.st_mode)) {
      return MP_IMPORT_STAT_DIR;
    } else if (S_ISREG(st.st_mode)) {
      return MP_IMPORT_STAT_FILE;
    }
  }
  return MP_IMPORT_STAT_NO_EXIST;
}
#endif

void nlr_jump_fail(void *val) {
  printf("FATAL: uncaught NLR %p\n", val);
  exit(1);
}