Re: [Qemu-devel] [PATCH 01/20] Makefile: Allow CPU targets to reside in target/ folder, too

[Laurent Vivier]

Le 09/12/2016 à 17:51, Thomas Huth a écrit :
> On 09.12.2016 13:24, Laurent Vivier wrote:
>> Le 09/12/2016 à 13:17, Thomas Huth a écrit :
>>> To be able to compile the CPU targets from within a subfolder
>>> of the target/ folder, we've got to adapt the Makefile.target
>>> a little bit first. After this change, target CPUs can either
>>> reside in a target/xxx folder or continue to use the target-xxx
>>> scheme. The latter will be disabled once all targets have been
>>> moved.
>>>
>>> Signed-off-by: Thomas Huth <address@hidden>
>>> ---
>>>  Makefile.target | 10 ++++++++--
>>>  1 file changed, 8 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/Makefile.target b/Makefile.target
>>> index 7a5080e..90b25ae 100644
>>> --- a/Makefile.target
>>> +++ b/Makefile.target
>>> @@ -7,11 +7,17 @@ include config-target.mak
>>>  include config-devices.mak
>>>  include $(SRC_PATH)/rules.mak
>>>  
>>> +ifneq ($(wildcard $(SRC_PATH)/target/$(TARGET_BASE_ARCH)),)
>>> +TARGET_FOLDER=target/$(TARGET_BASE_ARCH)
>>> +else
>>> +TARGET_FOLDER=target-$(TARGET_BASE_ARCH)
>>> +endif
>>
>> Perhaps you should consider to use ':=' instead of '='.
> 
> Most of the other variables in that file seem to be set with '=' instead
> of ':=', so using '=' sounds more consistent to me ... is there a real
> benefit of using ':=' here?

With ':=' your variable is expanded once, with '=' it is expanded
whenever it is used. I think this is not needed in your case.

https://www.gnu.org/software/make/manual/html_node/Flavors.html#Flavors

Thanks,
Laurent