bindings.rs

#[repr(C)]
#[derive(Debug, Copy)]
pub struct specbinding {
    pub _bitfield_1: u8,
    pub unwind: __BindgenUnionField<specbinding__bindgen_ty_1>,
    pub unwind_ptr: __BindgenUnionField<specbinding__bindgen_ty_2>,
    pub unwind_int: __BindgenUnionField<specbinding__bindgen_ty_3>,
    pub unwind_void: __BindgenUnionField<specbinding__bindgen_ty_4>,
    pub let_: __BindgenUnionField<specbinding__bindgen_ty_5>,
    pub bt: __BindgenUnionField<specbinding__bindgen_ty_6>,
    pub bindgen_union_field: [u64; 5usize],
}

lisp.h

union specbinding
  {
    ENUM_BF (specbind_tag) kind : CHAR_BIT;
    struct {
      ENUM_BF (specbind_tag) kind : CHAR_BIT;
      void (*func) (Lisp_Object);
      Lisp_Object arg;
    } unwind;
    struct {
      ENUM_BF (specbind_tag) kind : CHAR_BIT;
      void (*func) (void *);
      void *arg;
    } unwind_ptr;
    struct {
      ENUM_BF (specbind_tag) kind : CHAR_BIT;
      void (*func) (int);
      int arg;
    } unwind_int;
    struct {
      ENUM_BF (specbind_tag) kind : CHAR_BIT;
      void (*func) (void);
    } unwind_void;
    struct {
      ENUM_BF (specbind_tag) kind : CHAR_BIT;
      /* `where' is not used in the case of SPECPDL_LET.  */
      Lisp_Object symbol, old_value, where;
      /* Normally this is unused; but it is set to the symbol's
	 current value when a thread is swapped out.  */
      Lisp_Object saved_value;
    } let;
    struct {
      ENUM_BF (specbind_tag) kind : CHAR_BIT;
      bool_bf debug_on_exit : 1;
      Lisp_Object function;
      Lisp_Object *args;
      ptrdiff_t nargs;
    } bt;
  };