https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61444
--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> --- Created attachment 32908 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=32908&action=edit show_all_undeclared Patch that adds the -fno-show-all-undeclared option to show all instances of an undeclared variable in a function.
