New types printf_arginfo_size_function, printf_va_arg_function.
Declare register_printf_specifier, register_printf_modifier,
register_printf_type.
* stdio-common/printf-parse.h (struct printf_spec): Add size element.
(union printf_arg): Add pa_user element.
Adjust __printf_arginfo_table type.
Add __printf_va_arg_table, __printf_modifier_table,
__handle_registered_modifier_mb, and __handle_registered_modifier_wc
declarations.
* stdio-common/printf-parsemb.c: Recognize registered modifiers.
If registered arginfo call failed try normal specifier.
* stdio-common/printf-prs.c: Pass additional parameter to arginfo
function.
* stdio-common/Makefile (routines): Add reg-modifier and reg-type.
* stdio-common/Versions: Export register_printf_modifier,
register_printf_type, and register_printf_specifier for GLIBC_2.10.
* stdio-common/reg-modifier.c: New file.
* stdio-common/reg-type.c: New file.
* stdio-common/reg-printf.c (__register_printf_specifier): New
function. Mostly the old __register_printf_function function but
uses locking and type of third parameter changed.
(__register_printf_function): Implement using
__register_printf_specifier.
* stdio-common/vfprintf.c (vfprintf): Collect argument sizes in
calls to arginfo functions. Allocate enough memory for user-defined
types. Call new va_arg functions to get user-defined types.
Try installed handlers even for existing format specifiers first.