[Bug middle-end/54582] gap in FORTIFY checking of buffer lengths

[dcb314 at hotmail dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54582

--- Comment #11 from David Binderman <dcb314 at hotmail dot com> 2013-02-06 18:47:37 UTC ---
>It isn't that easy.  For %'s you really have to parse all the characters after
>% and figure out where the format specifier ends.

Agreed. But it doesn't have to be perfect, it just has to be
better than the previous solution. This is only a warning we are discussing.
It can be ignored. 

The Werror folks are, IMHO, far too keen for their own good.

I wrote:
>All the numeric specifiers (%d, %u etc) all produce at least one 
>character, so gcc could take account of this in checking buffer lengths.

In computing a lower bound, all % specifiers could be assumed to 
produce at least one byte of output.

Parsing the % specifier doesn't have to be perfect, it just has
to understand the common cases (%s, %d, %u etc) and punt on the rest.

More understanding can be added in later versions.