Checking wide format strings

["Joseph S. Myers" <jsm28 at cam dot ac dot uk>]

I'm thinking of adding support for checking formats passed to the wide
character formatted I/O functions (wprintf, wscanf, wscftime, etc.).  A
couple of questions:

1. Could someone add the relevant information where c-tree.texi says

	FIXME: How are wide strings represented?

?  While you're about it, information about the representation of string
literals for targets with wider than 8-bit char might be appropriate as
well.

2. Do people prefer having three new format attributes (wprintf, wscanf,
wcsftime) [glibc currently has such attributes, commented out as they're
not in GCC]; an attribute wformat (taking parameters either printf, scanf,
strftime or wprintf, wscanf, wcsftime); or overloading the format
attributes printf, scanf, strftime according to whether the type of the
corresponding parameter is a pointer to char or to wchar_t?

-- 
Joseph S. Myers
jsm28@cam.ac.uk