Re: [PATCH] file: remove the original magic.h

[Junling Zheng <zhengjunling@huawei.com>]

On 2015/3/28 19:05, Richard Purdie wrote:
> On Sat, 2015-03-28 at 17:37 +0800, Junling Zheng wrote:
>> On 2015/3/28 16:53, Richard Purdie wrote:
>>> On Sat, 2015-03-28 at 10:36 +0800, Junling Zheng wrote:
>>> We ran into this problem in our branches. You need to ensure that your
>>> CVE patches just touch magic.h.in and *not* magic.h. If you do that, the
>>> timestamp of magic.h.in will be more recent that magic.h and your build
>>> will function correctly.
>>>
>>> The problem is that patch can patch those two files "at the same time"
>>> on fast machines. You should never patch generated filed in patches in
>>> OE in general.
>>>
>>> Cheers,
>>>
>>> Richard
>>>
>> Hi, Richard
>>
>> You're right. My CVE patches indeed touch the original magic.h, and that's also why this problem reproduces probabilistic.
>>
>> I remove the modifying of magic.h in my patches, and this problem seems to be fixed.
>>
>> However, I still think the origin magic.h is confusing and redundant...:)
> 
> There is actually more to this. magic.h is listed as a BUILT_SOURCES
> file which means it is not regenerated by the usual dependency magic and
> timestamps, only if it doesn't exist or you run make all/check/install.
> 
> http://www.gnu.org/software/automake/manual/html_node/Sources.html
> 
> So you do need it in your patch however you need to ensure your patch
> generates a magic.h which matches magic.h.in.
> 
> Cheers,
> 
> Richard
> 
I get it!

Thanks a lot for your detailed explanation:)

Cheers,

Junling