Re: [dpdk-dev] [PATCH v3 1/5] mk: remove combined library and related options

["Gonzalez Monroy, Sergio" <sergio.gonzalez.monroy@intel.com>]

On 09/04/2015 14:33, Thomas Monjalon wrote:
> 2015-04-09 07:19, Neil Horman:
>> On Thu, Apr 09, 2015 at 12:06:47PM +0300, Avi Kivity wrote:
>>> On 04/09/2015 11:33 AM, Gonzalez Monroy, Sergio wrote:
>>>> On 08/04/2015 19:26, Stephen Hemminger wrote:
>>>>> On Wed,  8 Apr 2015 16:07:21 +0100
>>>>> Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com> wrote:
>>>>>
>>>>>> Currently, the target/rules to build combined libraries is different
>>>>>> than the one to build individual libraries.
>>>>>>
>>>>>> By removing the combined library option as a build configuration option
>>>>>> we simplify the build pocess by having a single point for
>>>>>> linking/archiving
>>>>>> libraries in DPDK.
>>>>>>
>>>>>> This patch removes CONFIG_RTE_BUILD_COMBINE_LIB build config option and
>>>>>> removes the makefiles associated with building a combined library.
>>>>>>
>>>>>> The CONFIG_RTE_LIBNAME config option is kept as it will be use to
>>>>>> always generate a linker script that acts as a single combined library.
>>>>>>
>>>>>> Signed-off-by: Sergio Gonzalez Monroy
>>>>>> <sergio.gonzalez.monroy@intel.com>
>>>>> No. We use combined library and it greatly simplfies the application
>>>>> linking process.
>>>>>
>>>> After all the opposition this patch had in v2, I did explain the current
>>>> issues
>>>> (see http://dpdk.org/ml/archives/dev/2015-March/015366.html ) and this was
>>>> the agreed solution.
>>>>
>>>> As I mention in the cover letter (also see patch 2/5), building DPDK
>>>> (after applying this patch series) will always generate a very simple
>>>> linker script that behaves as a combined library.
>>>> I encourage you to apply this patch series and try to build your app
>>>> (which links against combined lib).
>>>> Your app should build without problem unless I messed up somewhere and it
>>>> needs fixing.
>>> Is it possible to generate a pkgconfig file (dpdk.pc) that contains all of
>>> the setting needed to compile and link with dpdk?  That will greatly
>>> simplify usage.
>>>
>>> A linker script is just too esoteric.
>>>
>> Why esoteric?  We're not talking about a linker script in the sense of a binary
>> layout file, we're talking about a prewritten/generated libdpdk_core.so that
>> contains linker directives to include the appropriate libraries.  You link it
>> just like you do any other library, but it lets you ignore how they are broken
>> up.
>>
>> We could certainly do a pkg-config file, but I don't think thats any more
>> adventageous than this solution.
> As already commented (http://dpdk.org/ml/archives/dev/2015-March/015367.html),
I misunderstood the pkgconfig reference in your previous comment.
It seems even more trivial to generate the 'combined' linker script lib 
having a pkg-config file.
We could simplify much of the rte.app.mk by using a pkg-config file.

Sergio
> pkgconfig could be something useful in any case (single or multi-libraries).
> Having a linker script to replace the single ("combined") library may be
> convenient in some cases but do not replace pkgconfig.
>