--- a/configure.ac 2019-04-19 16:27:52.000000000 +0900 +++ b/configure.ac 2019-04-19 16:26:06.000000000 +0900 @@ -39,6 +39,20 @@ AC_PROG_LN_S dnl Compiling with per-target flags requires AM_PROG_CC_C_O. AC_PROG_CC AM_PROG_CC_C_O + +# Check if a compiler supports "-Wno-error=address-of-packed-member" +# If it supports the option, we add it to CFLAGS. +ac_save_CFLAGS="$CFLAGS" +AC_LANG_PUSH([C]) +CFLAGS="-Wno-error=address-of-packed-member" +AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[[]])], +[ac_c_recognize_address_of_packed_member=1], +[ac_c_recognize_address_of_packed_member=0]) +AC_LANG_POP([C]) +AS_IF([test $ac_c_recognize_address_of_packed_member -eq 1], +[CFLAGS="$ac_save_CFLAGS -Wno-error=address-of-packed-member"], +[CFLAGS="$ac_save_CFLAGS"]) + AC_PROG_LIBTOOL AC_PROG_CXX AC_PROG_INSTALL