__attribute__((constructor, used)) doesn't work if build with static lib of odp-dpdk

[lvsgate]

odp-dpdk version: 1.15.0.0_DPDK_17.02

1. configure --disable-shared for odp-dpdk and build
2. build ofp with odp-dpdk
3. run any example app of ofp and got the result
   "odp_packet_dpdk.c:162:setup_pkt_dpdk():No driver found for interface: 0"
4. It seems that RTE_PMD_REGISTER_PCI(net_ixgbe, rte_ixgbe_pmd.pci_drv) only be called in shared library

[MatiasElo]

This happens also with odp-linux when using DPDK pktio andit is likely caused by OFP not properly importing flags from libodp-linux.pc/libodp-dpdk.pc. I'm in the middle of porting patches from odp-linux to bring odp-dpdk up to date, but setting "PKG_CONFIG="pkg-config --static"" environment variable fixed driver linking with odp-linux.

[lumag]

pkg-config --static should only be necessary if one is building static app. It is needed to satisfy linking.
@MatiasElo Could you please provide minimal example that we can use to verify static linking with ODP/DPDK (in odp-linux case).

[lumag]

Regarding odp-dpdk. I remember doing several iterations with odp-linux/dpdk till I was able to fix possible app.odp/dpdk linking cases.

[MatiasElo]

@lumag I assumed OFP was built is static as ODP was build with '--disable-shared'.

I've used OFP's fpm_burstmode example to verify driver linking. E.g.
./fpm_burstmode -i 0,1 -c 1

[MatiasElo]

Fixed by #79.