Re: [PATCH liburing 2/2] src/Makefile: Add header files as dependency

[Ammar Faizi <ammarfaizi2@gnuweeb.org>]

On 3/9/22 7:23 AM, Alviro Iskandar Setiawan wrote:
> On Wed, Mar 9, 2022 at 6:06 AM Alviro Iskandar Setiawan wrote:
>> On Wed, Mar 9, 2022 at 5:52 AM Ammar Faizi wrote:
>>> This is ugly, it blindly adds all of them to the dependency while
>>> they're actually not dependencies for all the C files here. For
>>> example, when compiling for x86, we don't touch aarch64 files.
>>>
>>> It is not a problem for liburing at the moment, because we don't
>>> have many files in the src directory now. But I think we better
>>> provide a long term solution on this.
>>>
>>> For the headers files, I think we should rely on the compilers to
>>> generate the dependency list with something like:
>>>
>>>      "-MT ... -MMD -MP -MF"
>>>
>>> Then include the generated dependency list to the Makefile.
>>>
>>> What do you think?
>>
>> Yes, I think it's better to do that. I'll fix this in v2.
>> thx
> 
> Sir, I am a bit confused with the include dependency files to the Makefile.
> 
> I use like this:
> 
>     -MT <object_filename> -MMD -MP -MF <dependency_file>
> 
> the dependency file is generated, but how to include them dynamically?
> I think it shouldn't be included one by one.
> 
> So after this
> 
>     [...] -MT "setup.os" -MMD -MP -MF ".deps/setup.os.d" [...]
>     [...] -MT "queue.os" -MMD -MP -MF ".deps/queue.os.d" [...]
>     [...] -MT "register.os" -MMD -MP -MF ".deps/register.os.d" [...]
>     [...] -MT "syscall.os" -MMD -MP -MF ".deps/syscall.os.d" [...]
> 
> files .deps/{setup,queue,registers,syscall}.os.d are generated, but I
> have to include them to Makefile right? How to include them all at
> once?

Untested, but I think you can do something like:

   -include $(liburing_objs:%=.deps/%.d)

where liburing_objs is the variable that contains:
{setup,queue,registers,syscall}.os.

-- 
Ammar Faizi