#include <stdint.h>
  #include <stdio.h>
  #include <string.h>
  #include <setjmp.h>
  
  #include "py/nlr.h"
  #include "py/compile.h"
  #include "py/runtime.h"
  #include "py/repl.h"
  #include "py/gc.h"
  #include "py/mperrno.h"
  
  typedef jmp_buf regs_t;
  
  STATIC void gc_helper_get_regs(regs_t arr) {
    setjmp(arr);
  }
  
  static char * python_stack_top = NULL;
  
  void mp_port_init_stack_top() {
    char dummy;
    python_stack_top = &dummy;
  }
  
  void gc_collect(void) {
    assert(python_stack_top != NULL);
    gc_collect_start();
  
    /* get the registers.
     * regs is the also the last object on the stack so the stack is bound by
     * &regs and python_stack_top. */
    regs_t regs;
    gc_helper_get_regs(regs);
  
    void **regs_ptr = (void**)(void*)&regs;
    gc_collect_root(regs_ptr, ((uintptr_t)python_stack_top - (uintptr_t)&regs) / sizeof(uintptr_t));
  
    gc_collect_end();
  }
  
  mp_lexer_t *mp_lexer_new_from_file(const char *filename) {
      mp_raise_OSError(MP_ENOENT);
  }
  
  mp_import_stat_t mp_import_stat(const char *path) {
      return MP_IMPORT_STAT_NO_EXIST;
  }
  
  mp_obj_t mp_builtin_open(size_t n_args, const mp_obj_t *args, mp_map_t *kwargs) {
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(mp_builtin_open_obj, 1, mp_builtin_open);
  
  void nlr_jump_fail(void *val) {
      while (1);
  }