Make printf safe

[Paul Backus]

On Tuesday, 16 July 2024 at 01:22:14 UTC, Walter Bright wrote:
>> I suppose we could have the compiler insert a bounds check, in 
>> addition to all of the other rewrites, but at this point, it 
>> feels like we're not really calling printf at all; we're 
>> calling some other formatted-output function that's stolen 
>> printf's identity.
>
> Wrapping APIs with a better interface is what we do all the 
> time :-/

Of course. What I find objectionable in this case is that (a) the 
better interface is implemented using a bunch of 
compiler-internal rewrites, rather than normal D code; and (b) it 
shadows the existing C printf function rather than existing 
alongside it.

If we need a safer printf for DMD that doesn't carry all the 
bloat and baggage of Phobos's writef, then by all means, let's 
write one. But let's write it in D and put it in a normal D 
module, instead of sneaking around and redefining printf behind 
our users' backs.