Re: [RFC][PATCH] A generic boolean

Jes Sorensen
2006-08-04T14:03:11Z

>>>>> "Jeff" == Jeff Garzik <jeff@garzik.org> writes:

Jeff> ricknu-0@student.ltu.se wrote:
>> A first step to a generic boolean-type. The patch just introduce
>> the bool (in

Jeff> Since gcc supports boolean types and can optimize for such,
Jeff> introducing bool is IMO a good thing.

>> -Why would we want it? -There is already some how are depending on
>> a "boolean"-type (like NTFS). Also, it will clearify functions who
>> returns a boolean from one returning a value, ex: bool it_is_ok();
>> char it_is_ok(); The first one is obvious what it is doing, the
>> secound might return some sort of status.

Jeff> A better reason is that there is intrinsic compiler support for
Jeff> booleans.

Well late to the dicussion, but I still want to point out that forcing
a boolean type of a different size upon existing kernel code is not
always a great idea and can have nasty side effects for struct
alignments. Not to mention that on some architectures, accessing a u1
is a lot slower than accessing an int. If a developer really wants to
use the smaller type he/she should do so explicitly being aware of the
impact.

The kernel is written in C, not C++ or Jave or some other broken
language and C doesn't have 'bool'. This patch falls under the
'typedefs considered evil' or typedef for the sake of typedef, if you
ask me.

Regards,
Jes