[Mesa-dev] [PATCH 1/2] build libgallium shared by default.

[Andreas Boll]

2013/3/19 Maarten Lankhorst <maarten.lankhorst at canonical.com>:
> Op 18-03-13 16:28, Andreas Boll schreef:
>> 2013/3/18 Maarten Lankhorst <maarten.lankhorst at canonical.com>:
>>> This is one of the 2 patches used in ubuntu for decreasing size of mesa build.
>>>
>>> The other one is more hacky, and links libmesagallium into libgallium,
>>> and then links libgallium against libdricore too for minimal duplication.
>>>
>>> This might mess up with static llvm, iirc static llvm is built wrong and
>>> linking libgallium against it will cause it to export all llvm symbols too.
>>> I believe that this is a bug in llvm though, not in mesa. The static libraries
>>> should not export all llvm symbols.
>>>
>>> I should probably change the default to not building shared gallium for the
>>> same reason. :-)
>>>
>>> Meant mostly for discussion purposes, although if there is no objection I'll
>>> change the default to disabling shared gallium, and just let every distro enable
>>> shared llvm and libgallium for themselves.
>>>
>>>> 8---
>>> Signed-off-by: Maarten Lankhorst <maarten.lankhorst at canonical.com>
>>>
>>> --- a/configure.ac
>>> +++ b/configure.ac
>>> @@ -733,6 +733,19 @@
>>>  fi
>>>  AM_CONDITIONAL(HAVE_SHARED_GLAPI, test "x$enable_shared_glapi" = xyes)
>>>
>>> +AC_ARG_ENABLE([shared-gallium],
>>> +    [AS_HELP_STRING([--enable-shared-gallium],
>>> +        [Enable shared gallium core @<:@default=yes@:>@])],
>>> +    [enable_shared_gallium="$enableval"],
>>> +    [enable_shared_gallium=yes])
>>> +
>> The following code could be simplified...
>>
>>> +SHARED_GALLIUM="0"
>>> +if test "x$enable_shared_gallium" = xyes; then
>>> +    SHARED_GALLIUM="1"
>>> +fi
>>> +AC_SUBST([SHARED_GALLIUM])
>>> +AM_CONDITIONAL(HAVE_SHARED_GALLIUM, test $SHARED_GALLIUM = 1)
>>> +
>> ... to:
>>
>> AM_CONDITIONAL(HAVE_SHARED_GALLIUM, test "x$enable_shared_gallium" = xyes)
>>
> Woops you're right, this was a leftover from when the patch was a lot more invasive,
> and had to touch configs/autoconf.in too.
> The AM_CONDITIONAL was added later during the transition to 9.0 :-)
>
> Any thoughts on making shared gallium default or not? I'm thinking not because
> of the llvm symbol bug I mentioned above, unless we change the default
> of llvm shared libs to enabled too.
>
> ~Maarten

I think you should disable it by default since I want to cherry-pick
this patch to mesa 9.1.
We could always enable it by default later.
Additionally you should check if someone wants to build
enabled-shared-gallium with static llvm.
Then configure should print an error like this "Please use shared-llvm
if you want to enable shared-gallium,
since the combination static-llvm and shared-gallium is not supported"

Andreas.