https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90330
--- Comment #26 from Matt Thompson <matthew.thompson at nasa dot gov> --- (In reply to Iain Sandoe from comment #25) > > > Thanks for the explanations. I'm trying a new build now with gcc-8.2.0 as > > the compiler passed to configure. > > > > Here's a(nother dumb) question: let's assume everything works. How exactly > > can one see what the sysroot is on a compiler? I.e., I could run "gcc-8.2.0 > > -xyz" and see it looks for /usr/include, but "gcc-9.2.0 -xyz" would show the > > /Library/Developer... > > gcc --print-sysroot > > gcc --help will show you the things that the driver can print for you and > point to other help lines that might be useful. Ah. Should have figure that out myself. :shame: > > > > Oh, yes. I was thinking of things we'll be building with this new GCC. I > > just wish I could figure out the build-with-clang issue. It's like it's > > missing some C++ library in its link line: > > build with clang should (does for me) work :) Lucky you. :) My laptop and gcc have some sort of shining thing going on. I can't build gcc with Spack either. > > > Now, I do think it's a bit odd that 'main.o' is *after* 'libbackend.a' as I > > usually put all my .o first then my .a when I build, but I think that's just > > stylistic. > > Actually, one difference from the "usual linker" rules on Darwin is that > ld64 will repeatedly re-visit presented libraries (in their presented order) > to satisfy symbols. There is no need for the dance of repeating .a files > several times. Huh. Good to know! > > > > Plus the C++ is so dense I don't know what this is looking for: > > > > std::__detail::_List_node_base::_M_hook(std::__detail::_List_node_base*)", > > referenced from: > > ipa_icf::sem_item_optimizer::worklist_push(ipa_icf::congruence_class*) > > in libbackend.a(ipa-icf.o) > > TBH, neither do I from that snippet - but I do think that a correctly > installed command line tools should just succeed with. > > configure --prefix=/somewhere/nice > --with-sysroot=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk > > and use clang as the bootstrap compiler. > > [as an aside, I do wonder where you are getting your GMP, MPFR, MPC and > (optionally) ISL from ?] - for the record I usually build them in-tree and > thus they are bootstrapped with the compiler. I get those guys by running: ./contrib/download_prerequisites when I first get the source. Maybe there's a better way? I think a recipe I found long ago did that, so I've just done the same thing myself as it seemed to work.
