wide string arguments.
Also simplify the code that handles length modifiers and make it
more conservative. For instance, be explicit about the modifiers
allowed for %d, rather than assuming that anything other than L,
q, t, or z implies an int argument.
arguments where the format string is obtained from user data, or
otherwise difficult to verify statically.
Example usage:
printf(fmtcheck(user_format, standard_format), arg1, arg2);
checks the format string user_format for consistency (same number/order/
type of format operators) with standard_format. If they differ,
standard_format is used instead to avoid potential crashes or security
violations.
Obtained from: NetBSD
Reviewed by: -arch