On Wed, Oct 02, 2019 at 02:43:48PM +0900, Junio C Hamano wrote:
> William Baker <williamtbakeremail@xxxxxxxxx> writes:
>
> > Although my debugger might not be the smartest, I haven't noticed any
> > downsides to switching this to an enum.
>
> Well, if you write
>
> enum { BIT_0 = 1, BIT_1 = 2, BIT_3 = 4 } var;
>
> it's pretty much a promise that the normal value for the var is one
> of these listed values to your readers. But bit flags are meant to
> be used combined (after all, they are cheaper alternative for 1-bit
> wide bitfields in a structure), so it is misleading to use enum as
> such.
Having the combination of enum constants with power-of-two values is
not misleading, but rather an idiom.
Back when debugging the racy split index issues I only saw gibberish
like this:
(gdb) p ce->ce_flags
$2 = 469762048
With an enum I now have this instead:
(gdb) p ce->ce_flags
$2 = (CE_MATCHED | CE_UPDATE_IN_BASE | CE_STRIP_NAME)
The latter is about as many times more readable as the int value of
that 'ce_flags'.
The sooner everyone gets on board with this the better.
