Re: [Xen-devel] Implementaiton of cc-option in Config.mk

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 15.03.18 at 12:22, <wei.liu2@xxxxxxxxxx> wrote:
> On Thu, Mar 15, 2018 at 02:45:15AM -0600, Jan Beulich wrote:
>> >>> On 14.03.18 at 18:11, <wei.liu2@xxxxxxxxxx> wrote:
>> > The implementation of cc-option (grepping the option being tested in
>> > output) in Config.mk now makes it not possible to detect if -Og is
>> > supported because "-Og" doesn't appear in the output if it is not
>> > supported. I suspect there will be other options that cc-option can't work
>> > with.
>> > 
>> > It is implemented like that because we try to detect -Wno-* option. But
>> > why is that important? Can't we just ignore -Wno-* if they aren't
>> > supported?
>> 
>> Well, the explanation for its behavior is given in the comment
>> next to its definition:
> 
> Yeah, I know that. I'm just not sure why nonexistent -Wno-* should be
> rejected. If there is no corresponding -W* option in the first place,
> -Wno-* shouldn't cause any difference in the end result.

The problem is that at least some compiler versions error on unknown
-Wno-* the first time they produce some (other) warning. Hence we
can't blindly pass -Wno-*.

Jan


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel