Will try to take care of those few but it is possible that it is few more possible ways to lower compile time warnings verbosity level.
[tkloczko@domek SPECS.fedora]$ grep CFLAGS * | grep -- -Wno alex4.spec: CFLAGS="$RPM_OPT_FLAGS -Wno-deprecated-declarations" alphabet-soup.spec: CFLAGS="$RPM_OPT_FLAGS -fsigned-char -Wno-deprecated-declarations" autogen.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-format-contains-nul" bamf.spec:CFLAGS="$RPM_OPT_FLAGS -Wno-error=deprecated-declarations" bigloo.spec:export CFLAGS="$RPM_OPT_FLAGS -D_FILE_OFFSET_BITS=64 -Wno-unused" binutils.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-error" binutils.spec:CFLAGS="$CFLAGS -O0 -ggdb2 -Wno-error -D_FORTIFY_SOURCE=0" bip.spec:make CFLAGS="$RPM_OPT_FLAGS -fPIE -Wno-unused-result" byzanz.spec:CFLAGS="%optflags -Wno-deprecated-declarations" byzanz.spec:CFLAGS="$CFLAGS -Wno-cast-align" cdrkit.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-error=format-security -fno-strict-aliasing" control-center.spec: CFLAGS="$RPM_OPT_FLAGS -Wno-error" crda.spec:export CFLAGS="%{optflags} -Wno-error=unused-const-variable" cross-binutils.spec: export CFLAGS="$RPM_OPT_FLAGS -Wno-unused-const-variable" crystal-stacker.spec: CFLAGS="$RPM_OPT_FLAGS -fsigned-char -Wno-char-subscripts" cstream.spec:%{__make} %{?_smp_mflags} CFLAGS="%{optflags} -Wall -Wextra -Wno-unused-parameter -Werror" cylindrix.spec:make CFLAGS="$RPM_OPT_FLAGS -Wno-pointer-sign" LIBS="-lm" dee.spec:export CFLAGS="%{optflags} -Wno-error=maybe-uninitialized" dpdk.spec:- Drop no longer needed -Wno-error=array-bounds from CFLAGS duel3.spec: CFLAGS="$RPM_OPT_FLAGS -fsigned-char -Wno-deprecated-declarations -Wno-non-virtual-dtor" ecl.spec: CFLAGS="%{optflags} -Wno-unused -Wno-return-type -Wno-unknown-pragmas" ecryptfs-utils.spec:export CFLAGS="$RPM_OPT_FLAGS -Werror -Wtype-limits -Wno-unused" evolution-data-server.spec:export CFLAGS="$RPM_OPT_FLAGS -DLDAP_DEPRECATED -fPIC -I%{_includedir}/et -Wno-deprecated-declarations" evolution-ews.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-deprecated-declarations" evolution-mapi.spec:export CFLAGS="$CFLAGS -Wno-deprecated-declarations" evolution.spec:CFLAGS="$RPM_OPT_FLAGS -fPIC -DLDAP_DEPRECATED -Wno-sign-compare -Wno-deprecated-declarations"; export CFLAGS evolution.spec:- added -Wno-sign-compare to CFLAGS flyingsaucersattack.spec: CFLAGS="$RPM_OPT_FLAGS -Wno-deprecated-declarations -Wno-deprecated -Wno-write-strings -Wno-unused-result -Wno-format-security" gdb.spec:CFLAGS="$CFLAGS -Wno-implicit-fallthrough" gnomint.spec:make %{?_smp_mflags} CFLAGS="%{optflags} -Wno-unused-but-set-variable" gperftools.spec:CFLAGS=`echo $RPM_OPT_FLAGS -fno-strict-aliasing -Wno-unused-local-typedefs -DTCMALLOC_LARGE_PAGES | sed -e 's|-fexceptions||g'` guacamole-server.spec:export CFLAGS="%{optflags} -Wno-error=deprecated-declarations" icecat.spec:export _WARNINGS_CFLAGS=" -Wno-unused -Wdeclaration-after-statement -Wempty-body -Wpointer-to-int-cast -Wtype-limits" icecat.spec:export _WARNINGS_CFLAGS=" -Wno-unused -Wdeclaration-after-statement -Wempty-body -Wpointer-to-int-cast -Wtype-limits" isomd5sum.spec:CFLAGS="$RPM_OPT_FLAGS -Wno-strict-aliasing"; export CFLAGS java-1.8.0-openjdk-aarch32.spec:EXTRA_CFLAGS="%ourcppflags -std=gnu++98 -Wno-error -fno-delete-null-pointer-checks -fno-lifetime-dse" java-1.8.0-openjdk.spec:EXTRA_CFLAGS="%ourcppflags -std=gnu++98 -Wno-error -fno-delete-null-pointer-checks -fno-lifetime-dse" knot.spec:CFLAGS="%{optflags} -DNDEBUG -Wno-unused" lacewing.spec: CFLAGS="$RPM_OPT_FLAGS -fsigned-char -Wno-deprecated-declarations" libappindicator.spec:export CFLAGS="%{optflags} $CFLAGS -Wno-deprecated-declarations" libappindicator.spec:export CFLAGS="%{optflags} $CFLAGS -Wno-deprecated-declarations" libdbusmenu.spec:export CFLAGS="%{optflags} -Wno-error=deprecated-declarations" libdbusmenu.spec:export CFLAGS="%{optflags} -Wno-error=deprecated-declarations" libfaketime.spec:cd src ; CFLAGS="%{optflags} -Wno-nonnull-compare -Wno-strict-aliasing" make %{?_smp_mflags} \ libindicator.spec:export CFLAGS="%{optflags} -Wno-error=deprecated-declarations" libindicator.spec:export CFLAGS="%{optflags} -Wno-error=deprecated-declarations" libopensync-plugin-gnokii.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-error" libopensync.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-error" libpolyxmass.spec:export CFLAGS="${RPM_OPT_FLAGS} -Wno-error" libs3.spec:sed -e 's!^CFLAGS +=!& %{optflags} -Wno-error=format-truncation!' \ lldb.spec:CFLAGS="%{optflags} -fno-strict-aliasing -Wno-error=format-security -fno-rtti" lldb.spec.2017-03-18:CFLAGS="%{optflags} -fno-strict-aliasing -Wno-error=format-security -fno-rtti" lldpad.spec:CFLAGS=${CFLAGS:-%optflags -Wno-error}; export CFLAGS; lpg.spec: LOCAL_CFLAGS="%{optflags} -Wno-strict-overflow" LOCAL_CXXFLAGS="%{optflags} -Wno-strict-overflow" lpg.spec: LOCAL_CFLAGS="%{optflags} -Wno-strict-overflow" LOCAL_CXXFLAGS="%{optflags} -Wno-strict-overflow" magicmaze.spec: CFLAGS="$RPM_OPT_FLAGS -fsigned-char -Wno-deprecated-declarations -I/usr/include/gstream" mc.spec:export CFLAGS="-D_FILE_OFFSET_BITS=64 -D_LARGEFILE_SOURCE $RPM_OPT_FLAGS -Wno-strict-aliasing" memkind.spec: --mandir=%{_mandir} CFLAGS="$RPM_OPT_FLAGS -std=gnu99 -Wno-error=nonnull-compare" memkind.spec: CFLAGS="$RPM_OPT_FLAGS -std=gnu99 -Wno-error=tautological-compare" mstflint.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-implicit-fallthrough" ncbi-blast+.spec:export CFLAGS="%{optflags} -Wno-narrowing" openfortivpn.spec:export CFLAGS="-Wno-unused-function %optflags" openni-primesense.spec:sed -i 's|make -j$(calc_jobs_number) -C ../Build|make -j$(calc_jobs_number) -C ../Build CFLAGS_EXT="%{optflags} -Wno-unknown-pragmas" LDFLAGS_EXT="%{optflags}" DEBUG=1|' RedistMaker openvas-gsa.spec:export CFLAGS="$RPM_OPT_FLAGS -Werror=unused-but-set-variable -lgpg-error -Wno-error=deprecated-declarations" openvas-libraries.spec: export CFLAGS="$RPM_OPT_FLAGS -Wno-unused-const-variable -Wno-error=misleading-indentation" overgod.spec: CFLAGS="$RPM_OPT_FLAGS -Wno-unused-but-set-variable" PREFIX=%{_prefix} pacman.spec:%configure --enable-debug --enable-doxygen CFLAGS="$CFLAGS -Wno-error" pam_radius.spec:make %{?_smp_mflags} CFLAGS="%{optflags} -Wall -fPIC -Wno-unused-but-set-variable -Wno-strict-aliasing" parted.spec:CFLAGS="$RPM_OPT_FLAGS -Wno-unused-but-set-variable"; export CFLAGS perl-PDL.spec:CFLAGS="%{optflags} -Wno-unused" php.spec:CFLAGS="$RPM_OPT_FLAGS -fno-strict-aliasing -Wno-pointer-sign" php.spec.2017-03-18:CFLAGS="$RPM_OPT_FLAGS -fno-strict-aliasing -Wno-pointer-sign" polymake.spec:export CFLAGS="%{optflags} -I%{_includedir}/eigen3 -Wno-unused-local-typedefs -fno-delete-null-pointer-checks" postfix.spec:- add -Wno-comment to CFLAGS procmail.spec:make RPM_OPT_FLAGS="$RPM_OPT_FLAGS %{?hardened_flags} -Wno-comments $(getconf LFS_CFLAGS)" procmail.spec:- add -Wno-comments to CFLAGS pwauth.spec:make %{?_smp_mflags} CFLAGS="${CFLAGS} -Wno-comment" LDFLAGS="${LDFLAGS}" pypy3.spec: export CFLAGS=$(echo "$CFLAGS" -Wno-unused -fPIC) pypy.spec: export CFLAGS=$(echo "$CFLAGS" -Wno-unused -fPIC) python-assimulo.spec:CFLAGS="%{optflags} -Wl,-z,relro -fPIC -Wl,-z,now -Wno-cpp" \ python-assimulo.spec:CFLAGS="%{optflags} -Wl,-z,relro -fPIC -Wl,-z,now -Wno-cpp" \ qpid-dispatch.spec: "-DCMAKE_C_FLAGS=$CFLAGS -Wno-error=switch" \ quassel-irssi.spec:SYSTEM_QUASSELC=1 CFLAGS="%{optflags} -Wno-implicit-fallthrough" LDFLAGS="%{__global_ldflags}" IRSSI_CFLAGS="%{optflags}" %make_build ratproxy.spec:make %{?_smp_mflags} CFLAGS="$RPM_OPT_FLAGS -D_GNU_SOURCE -Wno-pointer-sign" rott.spec: EXTRACFLAGS="$RPM_OPT_FLAGS -Wno-unused -Wno-pointer-sign" \ rott.spec: EXTRACFLAGS="$RPM_OPT_FLAGS -Wno-unused -Wno-pointer-sign" \ steadyflow.spec:CFLAGS="%{optflags} -Wno-unused-function -Wno-unused-but-set-variable -Wno-address" sway.spec:export CFLAGS="%{optflags} -Wno-error" sway.spec.2017-03-18:export CFLAGS="%{optflags} -Wno-error" tcpreplay.spec: -e 's/^CFLAGS.*/CFLAGS=${RPM_OPT_FLAGS} -std=gnu99 -D_U_="__attribute__((unused))" -Wno-format-contains-nul/' \ uw-imap.spec:export EXTRACFLAGS="$EXTRACFLAGS -Wno-pointer-sign" uwsgi.spec:CFLAGS="%{optflags} -Wno-error -Wno-unused-but-set-variable" python uwsgiconfig.py --build fedora.ini uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" %{__python3} uwsgiconfig.py --plugin plugins/python fedora python3 uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" %{__python3} uwsgiconfig.py --plugin plugins/tornado fedora tornado3 uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/mongodblog fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable -std=gnu++11 -Wno-error" python uwsgiconfig.py --plugin plugins/stats_pusher_mongodb fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/mono fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/v8 fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/gccgo fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/fiber fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/rbthreads fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/systemd_logger fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/tuntap fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/psgi fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/coroae fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/logzmq fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/mongrel2 fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/greenlet fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/glusterfs fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/gridfs fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/jvm fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/jwsgi fedora uwsgi.spec:CFLAGS="%{optflags} -Wno-unused-but-set-variable" python uwsgiconfig.py --plugin plugins/ring fedora vinagre.spec:export CFLAGS="%{optflags} -Wno-deprecated-declarations -Wno-format-nonliteral" vorbis-tools.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-error=format-security" vte291.spec:CFLAGS="%optflags -fPIE -DPIE -Wno-nonnull" \ wine.spec:export CFLAGS="`echo $RPM_OPT_FLAGS | sed -e 's/-Wp,-D_FORTIFY_SOURCE=2//'` -Wno-error" wine.spec:export CFLAGS="`echo $TEMP_CFLAGS | sed -e 's/-Wp,-D_FORTIFY_SOURCE=2//'` -Wno-error" xawtv.spec:export CFLAGS="$RPM_OPT_FLAGS -Wno-pointer-sign" xfce-theme-manager.spec:make %{?_smp_mflags} xfcethememanager_CFLAGS="%{optflags} -export-dynamic" xfcethememanager_CXXFLAGS="%{optflags} -export-dynamic" -Wunused -Wunused-function -Wno-unused-result xmlrpc-c.spec:- set -Wno-uninitialized CFLAGS; code contains lot of constructs xscreensaver.spec:export CFLAGS="$CFLAGS -Wno-long-long" xscreensaver.spec:export CFLAGS="$CFLAGS -Wno-variadic-macros" zasx.spec: CFLAGS="$RPM_OPT_FLAGS -fsigned-char -Wno-deprecated-declarations"