text: #include <mruby.h>
  #include <mruby/presym.h>
  #include <mruby/proc.h>
  #include <mruby/variable.h>
  
  /* provided by mruby-proc-ext */
  mrb_value mrb_proc_source_location(mrb_state *mrb, struct RProc *p);
  
  /* provided by mruby-binding-core */
  mrb_value mrb_binding_alloc(mrb_state *mrb);
  struct RProc *mrb_binding_wrap_lvspace(mrb_state *mrb, const struct RProc *proc, struct REnv **envp);
  
  static mrb_value
  mrb_proc_binding(mrb_state *mrb, mrb_value procval)
  {
    mrb_value binding = mrb_binding_alloc(mrb);
    const struct RProc *proc = mrb_proc_ptr(procval);
    struct REnv *env;
  
    mrb_value receiver;
    if (!proc || MRB_PROC_CFUNC_P(proc) || !proc->upper || MRB_PROC_CFUNC_P(proc->upper)) {
      env = NULL;
      proc = NULL;
      receiver = mrb_nil_value();
    }
    else {
      env = MRB_PROC_ENV(proc);
      mrb_assert(env);
      proc = proc->upper;
      receiver = MRB_ENV_LEN(env) > 0 ? env->stack[0] : mrb_nil_value();
    }
  
    proc = mrb_binding_wrap_lvspace(mrb, proc, &env);
    mrb_iv_set(mrb, binding, MRB_SYM(proc), mrb_obj_value((void *)proc));
    mrb_iv_set(mrb, binding, MRB_SYM(recv), receiver);
    mrb_iv_set(mrb, binding, MRB_SYM(env), mrb_obj_value(env));
    mrb_iv_set(mrb, binding, MRB_SYM(source_location), mrb_proc_source_location(mrb, mrb_proc_ptr(procval)));
    return binding;
  }
  
  void
  mrb_mruby_proc_binding_gem_init(mrb_state *mrb)
  {
    mrb_define_method(mrb, mrb->proc_class, "binding", mrb_proc_binding, MRB_ARGS_NONE());
  }
  
  void
  mrb_mruby_proc_binding_gem_final(mrb_state *mrb)
  {
  }
  