Jeff Garzik <jgarzik@pobox.com> writes:
|> On Mon, Feb 24, 2003 at 10:35:24PM +0100, Andreas Schwab wrote:
|> > Linus Torvalds <torvalds@transmeta.com> writes:
|> >
|> > |> Does gcc still warn about things like
|> > |>
|> > |> #define COUNT (sizeof(array)/sizeof(element))
|> > |>
|> > |> int i;
|> > |> for (i = 0; i < COUNT; i++)
|> > |> ...
|> > |>
|> > |> where COUNT is obviously unsigned (because sizeof is size_t and thus
|> > |> unsigned)?
|> > |>
|> > |> Gcc used to complain about things like that, which is a FUCKING DISASTER.
|> >
|> > How can you distinguish that from other occurrences of (int)<(size_t)?
|>
|> The bounds are obviously constant and unsigned at compile time.
But that's not the point. It's the runtime value of i that gets converted
(to unsigned), not the compile time value of COUNT. Thus if i ever gets
negative you have a problem.
Andreas.
-- Andreas Schwab, SuSE Labs, schwab@suse.de SuSE Linux AG, Deutschherrnstr. 15-19, D-90429 Nürnberg Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5 "And now for something completely different." - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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