Ben, Currently on Darwin and apparently Solaris as well, we have build failures when gcc trunk is built without resorting to --disable-multilib on hardware that doesn't support 64-bits. See PR21561. Jack ps I am told for example that the builds of gcc trunk fail on the non-EMT64 MacBook Pro in this fashion... checking whether the C compiler works... configure: error: cannot run C compiled programs. If you meant to cross compile, use `--host'. See `config.log' for more details. make[1]: *** [configure-target-libstdc++-v3] Error 1
Relevant lines from i386-apple-darwin8.8.1/x86_64/libstdc++-v3/ config.log: configure:2694: checking for C compiler default output file name configure:2697: /Users/sandro/z/./gcc/xgcc -B/Users/sandro/z/./gcc/ - B/usr/local/i386-apple-darwin8.8.1/bin/ -B/usr/loca l/i386-apple-darwin8.8.1/lib/ -isystem /usr/local/i386-apple- darwin8.8.1/include -isystem /usr/local/i386-apple-darwin8. 8.1/sys-include -m64 -O2 -g -O2 conftest.c >&5 configure:2700: $? = 0 configure:2746: result: a.out configure:2751: checking whether the C compiler works configure:2757: ./a.out ../../../../gcc-4.2/libstdc++-v3/configure: line 1: ./a.out: Bad CPU type in executable On Mon, Oct 09, 2006 at 09:15:50AM +1000, Ben Elliston wrote: > > Shouldn't configure in gcc be made to automatically test if -m64 > > is working on the build machine in question and automatically invoke > > --disable-multilib if not? > > The capability of the build system compiler is meaningless for > multilibs. Whether or not multilibbing will work depends on whether > -m64 is working in the newly built compiler. Right? > > Ben