text: /* Notes on passes:
   * We don't know exactly the opcodes in pass 1 because they depend on the
   * closing over of variables (LOAD_CLOSURE, BUILD_TUPLE, MAKE_CLOSURE), which
   * depends on determining the scope of variables in each function, and this
   * is not known until the end of pass 1.
   * As a consequence, we don't know the maximum stack size until the end of pass 2.
   * This is problematic for some emitters (x64) since they need to know the maximum
   * stack size to compile the entry to the function, and this affects code size.
   */
  
  typedef enum {
      PASS_1 = 1, // work out id's and their kind, and number of labels
      PASS_2 = 2, // work out stack size and code size and label offsets
      PASS_3 = 3, // emit code
  } pass_kind_t;
  
  typedef struct _emit_t emit_t;
  
  typedef struct _emit_method_table_t {
      void (*set_native_types)(emit_t *emit, bool do_native_types);
      void (*start_pass)(emit_t *emit, pass_kind_t pass, scope_t *scope);
      void (*end_pass)(emit_t *emit);
      bool (*last_emit_was_return_value)(emit_t *emit);
      int (*get_stack_size)(emit_t *emit);
      void (*set_stack_size)(emit_t *emit, int size);
  
      void (*load_id)(emit_t *emit, qstr qstr);
      void (*store_id)(emit_t *emit, qstr qstr);
      void (*delete_id)(emit_t *emit, qstr qstr);
  
      void (*label_assign)(emit_t *emit, int l);
      void (*import_name)(emit_t *emit, qstr qstr);
      void (*import_from)(emit_t *emit, qstr qstr);
      void (*import_star)(emit_t *emit);
      void (*load_const_tok)(emit_t *emit, mp_token_kind_t tok);
      void (*load_const_small_int)(emit_t *emit, int arg);
      void (*load_const_int)(emit_t *emit, qstr qstr);
      void (*load_const_dec)(emit_t *emit, qstr qstr);
      void (*load_const_id)(emit_t *emit, qstr qstr);
      void (*load_const_str)(emit_t *emit, qstr qstr, bool bytes);
      void (*load_const_verbatim_str)(emit_t *emit, const char *str); // only needed for emitcpy
      void (*load_fast)(emit_t *emit, qstr qstr, int local_num);
      void (*load_deref)(emit_t *emit, qstr qstr, int local_num);
      void (*load_closure)(emit_t *emit, qstr qstr, int local_num);
      void (*load_name)(emit_t *emit, qstr qstr);
      void (*load_global)(emit_t *emit, qstr qstr);
      void (*load_attr)(emit_t *emit, qstr qstr);
      void (*load_method)(emit_t *emit, qstr qstr);
      void (*load_build_class)(emit_t *emit);
      void (*store_fast)(emit_t *emit, qstr qstr, int local_num);
      void (*store_deref)(emit_t *emit, qstr qstr, int local_num);
      void (*store_name)(emit_t *emit, qstr qstr);
      void (*store_global)(emit_t *emit, qstr qstr);
      void (*store_attr)(emit_t *emit, qstr qstr);
      void (*store_subscr)(emit_t *emit);
      void (*store_locals)(emit_t *emit);
      void (*delete_fast)(emit_t *emit, qstr qstr, int local_num);
      void (*delete_deref)(emit_t *emit, qstr qstr, int local_num);
      void (*delete_name)(emit_t *emit, qstr qstr);
      void (*delete_global)(emit_t *emit, qstr qstr);
      void (*delete_attr)(emit_t *emit, qstr qstr);
      void (*delete_subscr)(emit_t *emit);
      void (*dup_top)(emit_t *emit);
      void (*dup_top_two)(emit_t *emit);
      void (*pop_top)(emit_t *emit);
      void (*rot_two)(emit_t *emit);
      void (*rot_three)(emit_t *emit);
      void (*jump)(emit_t *emit, int label);
      void (*pop_jump_if_true)(emit_t *emit, int label);
      void (*pop_jump_if_false)(emit_t *emit, int label);
      void (*jump_if_true_or_pop)(emit_t *emit, int label);
      void (*jump_if_false_or_pop)(emit_t *emit, int label);
      void (*setup_loop)(emit_t *emit, int label);
      void (*break_loop)(emit_t *emit, int label);
      void (*continue_loop)(emit_t *emit, int label);
      void (*setup_with)(emit_t *emit, int label);
      void (*with_cleanup)(emit_t *emit);
      void (*setup_except)(emit_t *emit, int label);
      void (*setup_finally)(emit_t *emit, int label);
      void (*end_finally)(emit_t *emit);
      void (*get_iter)(emit_t *emit); // tos = getiter(tos)
      void (*for_iter)(emit_t *emit, int label);
      void (*for_iter_end)(emit_t *emit);
      void (*pop_block)(emit_t *emit);
      void (*pop_except)(emit_t *emit);
      void (*unary_op)(emit_t *emit, rt_unary_op_t op);
      void (*binary_op)(emit_t *emit, rt_binary_op_t op);
      void (*compare_op)(emit_t *emit, rt_compare_op_t op);
      void (*build_tuple)(emit_t *emit, int n_args);
      void (*build_list)(emit_t *emit, int n_args);
      void (*list_append)(emit_t *emit, int list_stack_index);
      void (*build_map)(emit_t *emit, int n_args);
      void (*store_map)(emit_t *emit);
      void (*map_add)(emit_t *emit, int map_stack_index);
      void (*build_set)(emit_t *emit, int n_args);
      void (*set_add)(emit_t *emit, int set_stack_index);
      void (*build_slice)(emit_t *emit, int n_args);
      void (*unpack_sequence)(emit_t *emit, int n_args);
      void (*unpack_ex)(emit_t *emit, int n_left, int n_right);
      void (*make_function)(emit_t *emit, scope_t *scope, int n_dict_params, int n_default_params);
      void (*make_closure)(emit_t *emit, scope_t *scope, int n_dict_params, int n_default_params);
      void (*call_function)(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg);
      void (*call_method)(emit_t *emit, int n_positional, int n_keyword, bool have_star_arg, bool have_dbl_star_arg);
      void (*return_value)(emit_t *emit);
      void (*raise_varargs)(emit_t *emit, int n_args);
      void (*yield_value)(emit_t *emit);
      void (*yield_from)(emit_t *emit);
  } emit_method_table_t;
  
  void emit_common_load_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qstr);
  void emit_common_store_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qstr);
  void emit_common_delete_id(emit_t *emit, const emit_method_table_t *emit_method_table, scope_t *scope, qstr qstr);
  
  extern const emit_method_table_t emit_pass1_method_table;
  extern const emit_method_table_t emit_cpython_method_table;
  extern const emit_method_table_t emit_bc_method_table;
  extern const emit_method_table_t emit_native_x64_method_table;
  extern const emit_method_table_t emit_native_thumb_method_table;
  
  emit_t *emit_pass1_new(qstr qstr___class__);
  void emit_pass1_free(emit_t *emit);
  emit_t *emit_cpython_new(uint max_num_labels);
  emit_t *emit_bc_new(uint max_num_labels);
  emit_t *emit_native_x64_new(uint max_num_labels);
  emit_t *emit_native_thumb_new(uint max_num_labels);
  
  typedef struct _emit_inline_asm_t emit_inline_asm_t;
  
  typedef struct _emit_inline_asm_method_table_t {
      void (*start_pass)(emit_inline_asm_t *emit, pass_kind_t pass, scope_t *scope);
      void (*end_pass)(emit_inline_asm_t *emit);
      int (*count_params)(emit_inline_asm_t *emit, int n_params, mp_parse_node_t *pn_params);
      void (*label)(emit_inline_asm_t *emit, int label_num, qstr label_id);
      void (*op)(emit_inline_asm_t *emit, qstr op, int n_args, mp_parse_node_t *pn_args);
  } emit_inline_asm_method_table_t;
  
  extern const emit_inline_asm_method_table_t emit_inline_thumb_method_table;
  
  emit_inline_asm_t *emit_inline_thumb_new(uint max_num_labels);
  