[SOLVED] xorg-server build from abs fails

Question

Hi,
ever since I installed the update to gcc-5.1.0 the building of xorg-server from abs fails:
$ makepkg -s
CCLD libXextdpmsstubs.la
xvdisp.c: In function ‘XineramifyXv’:
xvdisp.c:1783:37: error: array subscript is above array bounds [-Werror=array-bounds]
if (MatchingAdaptors[k] && (MatchingAdaptors[k]->nPorts > j))
^
xvdisp.c:1784:31: error: array subscript is above array bounds [-Werror=array-bounds]
port->info[k].id = MatchingAdaptors[k]->base_id + j;
^
xvdisp.c:1786:31: error: array subscript is above array bounds [-Werror=array-bounds]
port->info[k].id = 0;
^
cc1: some warnings being treated as errors
Makefile:777: recipe for target 'xvdisp.lo' failed
make[1]: *** [xvdisp.lo] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [all-recursive] Error 1
==> ERROR: A failure occurred in build().
Aborting...
This happens for xorg-server-1.17.1-6 and up as well as for xorg-server-1.17.2-1 .
$ gcc --version
gcc (GCC) 5.1.0
Copyright (C) 2015 Free Software Foundation, Inc.
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
I searched for a solution or a patch, but couldn't find anything.
xorg-server-1.17.2 supposedly has build fixes with gcc-5.1, but obviously that didn't help much for me.
Otherwise my arch installation is up-to-date.
I'm building on x86-64 (Haswell) with
CPPFLAGS="-D_FORTIFY_SOURCE=2"
CFLAGS="-march=native -mtune=native -O3 -pipe -fstack-protector-strong --param=ssp-buffer-size=4"
CXXFLAGS="-march=native -mtune=native -O3 -pipe -fstack-protector-strong --param=ssp-buffer-size=4"
LDFLAGS="-Wl,-O2,--sort-common,--as-needed,-z,relro"
MAKEFLAGS="-j16"
DEBUG_CFLAGS="-g -fvar-tracking-assignments"
DEBUG_CXXFLAGS="-g -fvar-tracking-assignments"
Has anyone else seen this or any idea how to fix it?
Last edited by pgzh (2015-06-19 15:03:20)

Answer 1

Using
CFLAGS="-march=native -mtune=native -O2 -pipe -fstack-protector-strong --param=ssp-buffer-size=4"
CXXFLAGS="-march=native -mtune=native -O2 -pipe -fstack-protector-strong --param=ssp-buffer-size=4"
in makepkg.conf actually worked, I totally forgot about changing the optimization level.
Since this is the first time for a very long time I've encountered a problem with -O3, do you think this should be reported as a bug for xorg-server?
With gcc-4.9 building xorg-server with -O3 optimization level worked perfectly fine for me (I built 1.17.1 like that) and gcc-5.1 causes this culprit.
Anyways, thank you very much for your help!