build issues after 8211029 on gcc4.8 and our porting Linux platforms (ppc64(le)/ s390x)

[Baesken, Matthias]

Hello, it looks like

8211029: Have a common set of enabled warnings for all native libraries

breaks a lot of our Linux based builds.
Our gcc 4.8   misses some of the introduced command line options :

cc1plus: error: unrecognized command line option "-Wno-misleading-indentation" [-Werror]
cc1plus: error: unrecognized command line option "-Wno-implicit-fallthrough" [-Werror]
cc1plus: error: unrecognized command line option "-Wno-int-in-bool-context" [-Werror]

Additionally ,  the added -Werror=switch  triggers a LOT of errors on our  porting platforms, e.g.  linux ppc64 le :

/build_ci_jdk_jdk_linuxppc64le/src/hotspot/cpu/ppc/c1_LIRGenerator_ppc.cpp:719:10: error: enumeration value '_Double_valueOf' not handled in switch [-Werror=switch]
/build_ci_jdk_jdk_linuxppc64le/src/hotspot/cpu/ppc/c1_LIRGenerator_ppc.cpp:719:10: error: enumeration value '_forEachRemaining' not handled in switch [-Werror=switch]
/build_ci_jdk_jdk_linuxppc64le/src/hotspot/cpu/ppc/c1_LIRGenerator_ppc.cpp:719:10: error: enumeration value 'ID_LIMIT' not handled in switch [-Werror=switch]
/build_ci_jdk_jdk_linuxppc64le/src/hotspot/cpu/ppc/c1_LIRGenerator_ppc.cpp:719:10: error: enumeration value 'LAST_COMPILER_INLINE' not handled in switch [-Werror=switch]
/build_ci_jdk_jdk_linuxppc64le/src/hotspot/cpu/ppc/c1_LIRGenerator_ppc.cpp:719:10: error: enumeration value 'FIRST_MH_SIG_POLY' not handled in switch [-Werror=switch]
/build_ci_jdk_jdk_linuxppc64le/src/hotspot/cpu/ppc/c1_LIRGenerator_ppc.cpp:719:10: error: enumeration value 'FIRST_MH_STATIC' not handled in switch [-Werror=switch]
/build_ci_jdk_jdk_linuxppc64le/src/hotspot/cpu/ppc/c1_LIRGenerator_ppc.cpp:719:10: error: enumeration value 'LAST_MH_SIG_POLY' not handled in switch [-Werror=switch]
/build_ci_jdk_jdk_linuxppc64le/src/hotspot/cpu/ppc/c1_LIRGenerator_ppc.cpp:719:10: error: enumeration value 'FIRST_ID' not handled in switch [-Werror=switch]

Could we get rid of  the  -Werror=switch   at least for now ?
Maybe it should be disabled for ppc64 / ppc64le  /  s390x  like it has been done for zero ?

4.13+
4.14 ifeq ($(call check-jvm-feature, zero), true)
4.15-  DISABLED_WARNINGS_gcc += return-type
4.16+  DISABLED_WARNINGS_gcc += return-type switch
4.17 endif


Regarding the unrecognized command line options ,  I suggest to still support older gcc versions;
what would be the minimal gcc version that supports 8211029 ?

Best regards, Matthias