The warning was:

------------------------
In file included from /roux/openairinterface5g/openair2/UTIL/LOG/log.h:306:0,
                 from /roux/openairinterface5g/openair1/PHY/defs.h:54,
                 from /roux/openairinterface5g/openair2/LAYER2/MAC/eNB_scheduler_ulsch.c:33:
/roux/openairinterface5g/openair2/UTIL/LOG/log.h: In function 'printMeas':
/roux/openairinterface5g/common/utils/T/T.h:94:26: warning: format not a string literal and no format arguments [-Wformat-security]
 #define T_ID(x) ((struct T_header *)(uintptr_t)(x))
                          ^
/roux/openairinterface5g/common/utils/T/T.h:29:22: note: in definition of macro 'T_PUT_int'
     int T_PUT_var = (val); \
                      ^
/roux/openairinterface5g/common/utils/T/T.h:269:7: note: in expansion of macro 'T_HEADER'
       T_HEADER(t); \
       ^
/roux/openairinterface5g/common/utils/T/T.h:101:76: note: in expansion of macro 'T3'
         n18,n19,n20,n21,n22,n23,n24,n25,n26,n27,n28,n29,n30,n31,n32,n,...) T##n
                                                                            ^
/roux/openairinterface5g/common/utils/T/T.h:102:16: note: in expansion of macro 'TN'
 #define T(...) TN(__VA_ARGS__)
                ^
/roux/openairinterface5g/openair2/UTIL/LOG/log.h:308:28: note: in expansion of macro 'T'
 #    define LOG_W(c, x...) T(T_LEGACY_ ## c ## _WARNING, T_PRINTF(x))
                            ^
/roux/openairinterface5g/common/utils/T/T_IDs.h:71:30: note: in expansion of macro 'T_ID'
 #define T_LEGACY_PHY_WARNING T_ID(68)
                              ^
/roux/openairinterface5g/openair2/UTIL/LOG/log.h:308:30: note: in expansion of macro 'T_LEGACY_PHY_WARNING'
 #    define LOG_W(c, x...) T(T_LEGACY_ ## c ## _WARNING, T_PRINTF(x))
                              ^
/roux/openairinterface5g/openair2/UTIL/LOG/log.h:411:9: note: in expansion of macro 'LOG_W'
         LOG_W(PHY,txt2);
------------------------

over and over.

By replacing LOG_W(PHY,txt2) by LOG_W(PHY,"%s",txt2) all the warnings
are removed.

The compilation line was:
    ./build_oai --eNB -w USRP

The file openairinterface5g/cmake_targets/log/lte-softmodem.Rel10.txt
has been checked and all LOG_X (and 'msg') warnings have been fixed.

Not sure that it's correct, but those #pragma seem
to be of no use for gcc. Let's remove them
completely.

This reverts commit d31634c3.

Laurent Thomas had a problem on one machine with the build_oai
way of checking for nettle.

The problem with the alternative solution of including nettle/bignum.h
is that it is very unclear.

The problem with nettle is that the file nettle/config.h does not
exist for version 2. It was introduced in version 3.

We want to support both versions, but there is an API incompatibility.
So we need an #if #else mechanism.

The file nettle/bignum.h is present in both versions 2 and 3 and it
includes nettle/version.h in the version 3.

So by including this file, we can check for the existence of
NETTLE_VERSION_MAJOR (that comes from nettle/config.h) in the
code.

But as you can see, the reasoning is way too complex.

So it's better to keep the check in cmake_targets/CMakeLists.txt.

As long as we support version 2 this will be the way to go.

It is possible to force a given version in specific non-generic
customized environments.

This commit follows 7d9945e8.

lte-softmodem UE in S1 and lte-softmodem UE in noS1 modes behave
differently here.

This commit fixes the issue for thoses cases.

Other cases (eNB S1, eNB noS1, oaisim S1/noS1) have to be checked.

This commit is a continuation of 614d6bbe
(ue_ip: use correct instance).

Now in openair2/NETWORK_DRIVER/UE_IP/common.c the 'inst' is not
forced to 1 anymore, we take the value 'pdcph_p->inst'.

It turns out that 'pdcph_p->inst' is 0 instead of 1 when we
run lte-softmodem as an UE.

So let's modify PDCP to set 'inst' to 1 where it was set to 0 for
the UE softmodem case, and skip the places where it is reset to 0,
still for the UE softmodem case.

This may break things, I am not sure.

The problem was the following.

Run oaisim with two UEs:

    sudo ../cmake_targets/oaisim_build_oai/build/oaisim -O enb.conf -u2 -s15 -AAWGN -y1 -b1 -Q0

Then wait for both UEs to be connected. The interfaces "oip1" and "oip2" are
activated, with IP addresses 192.172.0.2 for the first UE and 192.172.0.3 for
the second.

Then on the EPC machine, do:

    ping 192.172.0.3

No reply.
On the oaisim machine, we see that the packets are sent to "oip1" instead
of "oip2".

The fix may break softmodem UE. The inst was forced to "1" for some reason.
To be checked.