Cellular Network Infrastructure

I recently merged Change-Id I61997a3668cc3a40d12ca023272f6d782e6fbefe which adds code that uses constructs like "for (int i = 0; i < foo; i++)". Our gerrit build verification jobs had no problem with that, the patch got V+1 and I merged it.

Now the "master" jobs are failing like this:

osmo-config-merge.c: In function 'file_read':
osmo-config-merge.c:148:4: error: 'for' loop initial declarations are only allowed in C99 or C11 mode
    for (int i = 0; i < cur_indent - indent; i++) {
    ^
osmo-config-merge.c:148:4: note: use option -std=c99, -std=gnu99, -std=c11 or -std=gnu11 to compile your
code

so somehow the C standard / compiler flags between gerrit and master builds appear to be different.

For the full example, see https://jenkins.osmocom.org/jenkins/job/master-osmo-sgsn/IU=--enable-iu,a2=default,a3=default,label=osmocom-master-debian9/5782/display/redirect [dead link, already cleaned up]

We should fix this to ensure nothing passes gerrit build verification but later fails after being merged to master.

libosmocore is not built inside Docker (unlike some other Osmocom projects). So the buildbot's host GCC is used.

We have Debian 8 (jessie) and 9 (stretch) based build bots. Looking at the gcc versions:

• jessie (8) has GCC 4.x
• stretch (9) has GCC 6.x

In GCC-5, the default value for -std changed:

GCC defaults to -std=gnu11 instead of -std=gnu89.

So as I understand, in gerrit, your patches were compiled by chance with GCC-6.x on Debian stretch, and then in master with GCC-4.x where it complained about using C99 syntax.

We can probably set -std=... somewhere in the Makefiles.am to enforce having the same standard everywhere.

• https://packages.debian.org/search?keywords=gcc
• https://gcc.gnu.org/gcc-5/porting_to.html

I ran into a similar problem, and proposed to set the dialect in CFLAGS and CXXFLAGS for all projects:

https://lists.osmocom.org/pipermail/openbsc/2019-September/013030.html

This will be resolved with: https://gerrit.osmocom.org/c/osmo-ci/+/15584/7