Re: [PATCH] gimple-ssa-sprintf: Fix typo in range check

[Jakub Jelinek <jakub@redhat.com>]

On Fri, Jul 26, 2024 at 01:39:04PM -0400, Siddhesh Poyarekar wrote:
> > What exactly the code really wants to do is unclear to me, what does
> > the INT_MAX on the target have to do with the minimum/maximum/expected
> > sizes of %S or %ls printed strings is unclear, target PTRDIFF_MAX
> 
> I think that is because the printf family returns the number of bytes/chars
> written in an int, which imposes the INT_MAX limitation on the format string
> expansion.

Ah, yes, that makes sense.

> > maybe.  And why it uses this
> > 	  if (slen.range.something < target_int_max ())
> > 	    slen.range.something *= something_else;
> > rather than say
> > 	  slen.range.something
> > 	    = MIN (slang.range.something * something_else, target_int_max ());
> > perhaps with some overflow checking is also something that is hard to guess.
> 
> That's what I tried first but I settled for the minimal change because I
> didn't want to dig in deeper than I had time for to at the moment. Further
> down it checks if MAX and UNLIKELY cross INT_MAX and then resets to INT_MAX,
> but that looks suspicious on, e.g. 32-bit targets.  The code could use some
> refactoring/cleanup.

I think the counters are HOST_WIDE_INT or unsigned HOST_WIDE_INT, so always
64-bit.

	Jakub