Re: [dpdk-dev] Linking with -ldpdk

[Bruce Richardson <bruce.richardson@intel.com>]

On Mon, Feb 19, 2018 at 10:39:39AM +0100, tom.barbette@uliege.be wrote:
> Hi list,
> 
> I found out that to staticly compile against DPDK using the combined lib, I needed all these options :
> 
> -I${RTE_SDK}/${RTE_TARGET}/include -L${RTE_SDK}/${RTE_TARGET}/lib -Wl,--whole-archive -ldpdk -Wl,--no-whole-archive -lnuma -ldl -lpthread -lm -lmlx4 -lmlx5 -libverbs
> 
> The whole-archive makes sense, as we need to embed drivers that wouldn't be found at linking time (failing to include it prevents port discovery).
> However it leads to missing inclusion. That's why I added all the libs at the end of the line. The mlx4 libs particularly leads me to think that there must be a more programmatic way, portable accross versions of DPDK to find out which libraries referenced in DPDK I should include, right? Morveover if the DPDK user didn't include mlx4, it will fail to compile...
> 
> What should I use? (the whole rte.extapp.mk DPDK build process is not an option as the build system is rather complex in this project)
> 
> Or maybe some of these libraries should be included in the dpdk static lib?
> 
> I use the last git version (but it's the same problem with previous ones).
> 
> Thanks,
> 
> Tom

Hi Tom,

this is something that I was hoping to achieve using pkg-config files
generated by the meson build system. This is still a work in progress,
but you can use "ninja install" to install a pkg-config file for DPDK at
the end of the build process, and the Makefiles for the DPDK examples
show how to build a static binary using that information. 

Now the limitations: there is no support for building all of DPDK as a
single static library, but pkg-config does provide the list of all DPDK
libs and drivers individually, as well as a list of the extra lib names
that have to be added to the end. [Given what pkg-config provides, I
fail to see the need to produce the single .a file any more too] Sadly
for the use case you mention above, the mlx* drivers aren't available as
part of the build yet either.

In the meantime, while the gaps are being filled out, any feedback on
building using pkg-config output would be appreciated. I admit it is a
bit more geared towards shared library building, but static should work
also.

Regards,
/Bruce