GCC主要数据结构之C lang_type

struct GTY(()) lang_type {
  /* In a RECORD_TYPE, a sorted array of the fields of the type.  */
  struct sorted_fields_type * GTY ((reorder ("resort_sorted_fields"))) s;
  /* In an ENUMERAL_TYPE, the min and max values.  */
  tree enum_min;
  tree enum_max;
  /* In a RECORD_TYPE, information specific to Objective-C, such
     as a list of adopted protocols or a pointer to a corresponding
     @interface.  See objc/objc-act.h for details.  */
  tree objc_info;
};

/* Save and restore the variables in this file and elsewhere
   that keep track of the progress of compilation of the current function.
   Used for nested functions.  */
struct GTY(()) language_function {
  struct c_language_function base;
  tree x_break_label;
  tree x_cont_label;
  struct c_switch * GTY((skip)) x_switch_stack;
  struct c_arg_info * GTY((skip)) arg_info;
  int returns_value;
  int returns_null;
  int returns_abnormally;
  int warn_about_return_type;
};