On Thu, 13 Jun 2024 at 13:11, Klaus Rudolph via Gcc-help <gcc-help@xxxxxxxxxxx> wrote: > > I try to cross compile gcc 14.1.0 for an older arm linux. > > During compilation it fails with a long list of linking problems for > libstdc++.so > > I configured gcc with: > ../configure --prefix=/opt/armv7_$(GCC_VERSION) --enable-languages=c,c++ > --with-sysroot=/opt/podman_debian8/merged --enable-multiarch > --with-fpu=vfpv3-d16 --with-mode=thumb --with-arch=armv7-a > --target=arm-linux-gnueabihf --disable-multilib --with-stdc++lib=static > > Is it possible to add/remove some flags for ./configure to get the new > compiler to work even with the libm.a library from the target system > which was not compiled with fPic. I don't think so, no. If you don't have a dynamic library for libm, I don't think you'll be able to have a dynamic library for libstdc++ either. You could possibly modify the libstdc++ sources and/or build system to include dummy stub definitions of the libm functions in libstdc++.so, and not export them. But things might break if anything in libstdc++.so tried to actually use those stubs. You might also be able to change the build system so that libstdc++.so can be linked without those definitions, which would require the user program to link to libm later. I'm not sure how to do that. There are no configure flags to make this easy.
