https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51450
--- Comment #6 from Andrew Pinski <pinskia at gcc dot gnu.org> --- configure:18495: checking if gcc supports -fno-rtti -fno-exceptions configure:18513: gcc -c -g -fno-rtti -fno-exceptions conftest.c >&5 cc1: warning: command-line option '-fno-rtti' is valid for C++/D/ObjC++ but not for C configure:18517: $? = 0 configure:18530: result: no It should have used g++ here ... Note the previous one works though: configure:7500: checking whether gcc supports -fno-rtti configure:7517: gcc -c -fno-rtti conftest.c >&5 cc1: warning: command-line option '-fno-rtti' is valid for C++/D/ObjC++ but not for C configure:7517: $? = 0 configure:7526: result: yes https://lists.gnu.org/archive/html/libtool/2003-08/msg00003.html Looks like the issue upstream in libtool now the question comes is this fixed upstream or not. Note the test here is not an issue for GCC's builds in general due to the extra testing for -fno-rtti -fno-exceptions that gcc does but still an issue for the libtool that is included with gcc.
