[Mesa-dev] [PATCH 0/3] misc janitorial

[Emil Velikov]

On 30 November 2015 at 20:00, Ian Romanick <idr at freedesktop.org> wrote:
> On 11/29/2015 07:21 AM, Emil Velikov wrote:
>> Hi Giuseppe,
>>
>> On 28 November 2015 at 15:43, Giuseppe Bilotta
>> <giuseppe.bilotta at gmail.com> wrote:
>>> The second and third patches are mostly aimed at removing non-spurious
>>> compiler warnings. The first one is just minor whitespace cleanup in the
>>> general area of code touched by the second patch.
>>>
>>> Giuseppe Bilotta (3):
>>>   radeon: whitespace cleanup
>>>   radeon: const correctness
>>>   xvmc: force assertion in XvMC tests
>>>
>> With the small comment in patch 3 addressed the series is
>> Reviewed-by: Emil Velikov <emil.l.velikov at gmail.com>
>>
>> If you're looking for an easy task - there is one in radeon/r200.
>> Currently we have a lot of nasty in-tree symlinks, symbol duplication
>> and hacks to get around it. Let me know if you'd like more info/tips
>> on how to tackle it.
>
> This is something that has been annoying me a bit lately.  What do you
> think the right solution is?  The Intel driver used to have a common
> src/mesa/drivers/dri/intel directory that was compiled once and shared
> by i915 and i965.  The code paths started to diverge quite a lot, so we
> copied the shared files into each directory... and became non-shared.
> Note that we didn't rename any of the function names, so we still have
> the ugly hacks to get around the symbol duplication.
>
I'm not sure about "right and wrong" but the possible solution I was
thinking is the one you mentioned - have a common place where that
code is built once.

The long version:
 1. Grep for RADEON_R{1,2}00 and look at the guarded code
 1.1 Some guards can just be dropped (CHIP_FAMILY_*, get_chip_family_name),
 1.2 Other hunks of code can be split/moved into the respective
r100/r200 codebase (radeonTexBufferExtension and
r200TexBufferExtension).
 1.3 Or folded into the vtbl dispatch - get_depth_z32/16 or the
respective callers, depending on the overhead (neither one is likely
to be noticeable).
 2. Copy/pasta an existing radeon Makefile to radeon_common. Tweak to
produce an empty library and get it into the final mega_dri_drivers.so
 2.1 With most/all of the RADEON_R*00 guards gone, one should be able
to just git mv the files into the new location. (alongside dropping
the symlinks)
 2.2 Remove the symbol redefinition hack.

It's a lengthy task, yet relatively easy. As long one tries to divide
and concur, rather than understand, in depth, how the driver/autohell
buildsystem works :-)
I'm more than willing to help out on the lot (esp. the latter), just
shout when you get confused/stuck.

-Emil