2007-01-19 Basile Starynkevitch <basile@starynkevitch.net>

	* doc/gty.texi (Options): Document the mark_hook option to
	GTY.
	* gcc/gengtype.c (write_types_data, write_func_for_structure,
	write_types, ggc_wtd, pch_wtd): Added skip_hooks to
	write_types_data, ggc_wtd, pch_wtd for mark_hook.
	(walk_type, write_func_for_structure): Generate the mark_hook if
	needed.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@120974 138bc75d-0d04-0410-961f-82ee72b054a4