Re: [PATCH v3 07/25] sequencer: completely revamp the "todo" script parsing

From: Jeff King <peff@peff.net>
Date: Oct 15, 2016, 17:19 UTC
Message-ID: <20161015171926.qgtvrjcaqwb436hx@sigill.intra.peff.net>
In-Reply-To: <933b13d6-5f24-c03a-a1a0-712ceb8ddcc8@web.de>

On Sat, Oct 15, 2016 at 07:03:46PM +0200, Torsten Bögershausen wrote:

Show 7 quoted lines

> sequencer.c:633:14: warning: comparison of constant 2 with expression of type 'const enum todo_command' is always true [-Wtautological-constant-out-of-range-compare]
>         if (command < ARRAY_SIZE(todo_command_strings))
>             ~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 1 warning generated.
>
> 53f8024e (Johannes Schindelin   2016-10-10 19:25:07 +0200  633)         if (command < ARRAY_SIZE(todo_command_strings))
>

Interesting. The compiler is right that this _should_ never happen, but I think the patch is quite reasonable to be defensive in case the enum happens to get a value outside of its acceptable range (which is probably undefined behavior, but...).

I wonder if:

  if ((int)command < ARRAY_SIZE(todo_command_strings))

silences the warning (I suppose size_t is probably an even better type, though obviously it does not matter in practice).

-Peff