[U-Boot] [PATCH] dts/Makefile: Turn off system-/gcc-specific predefined macros

[Horst Kronstorfer <u-boot@aon.at>]

On 07/25/2012 06:06 PM, Mike Frysinger wrote:
> On Tuesday 24 July 2012 15:38:55 Horst Kronstorfer wrote:
>> On 07/24/2012 05:28 PM, Mike Frysinger wrote:
>>> On Tuesday 24 July 2012 06:11:04 Horst Kronstorfer wrote:
>>>> On 07/19/2012 05:22 AM, Mike Frysinger wrote:
>>>>> On Friday 13 July 2012 09:03:40 Horst Kronstorfer wrote:
>>>>>> Add '-undef' to DTS_CPPFLAGS to avoid unwanted expansion of dts
>>>>>> content that matches system-specific or gcc-specific predefined
>>>>>> macros.
>>>>>>
>>>>>> Example: A number of PowerPC related *.dts files in the kernel define
>>>>>> a property named 'linux,network-index' which (w/o '-undef') is
>>>>>> expanded to '1,network-index' by the preprocessor because of '#define
>>>>>> linux 1.'
>>>>>
>>>>> i think you should use -ansi instead.  that's what we use in other
>>>>> places for the same reason.
>>>>
>>>> this would increase the probability of a name clash.
>>>
>>> no idea what you're talking about.  have you actually looked at the
>>> output of `gcc -E -dD -ansi` ?
>>
>> $ gcc -E -dM -ansi - </dev/null | wc -l
>> 229
>> $ gcc -E -dM -undef - </dev/null | wc -l
>> 2
>
> and ?  did you *look* at the output ?  they're all of the form __foo__.

i already considered that.

> do any device trees really use __foo__ names ?  i don't think so.

is there any drawback using '-undef' in this particular case besides
"we use -ansi in other places for the same reason"?

-h

> -mike
>