On Thu, 20 Oct 2022 at 11:35, olologin via Gcc-help <gcc-help@xxxxxxxxxxx> wrote: > > Hi everyone, > I am kind of new to cross-compiling (if we can call my task like this), so > maybe my question is kind of stupid. > > I need to build my project for old runtimes (libstdc++, libgcc_s, etc) that > came with GCC 6, but I can build my sourcecode only with newest C++ > features, so I chose GCC 12 for this. > Of course my API is old enough to support GCC 6. And of course I am aware > of potential risks (like some implementations that can be missing in the > old runtime). > > Currently I am doing this in a very hacky way, and build my project in a > container that looks like this: > https://gist.github.com/olologin/b4ba2db91fc5c526d625715b39ac4579 > As you can see, starting from line 73 it gets hacky because I could not > find a better way to make sure GCC 12 links my code with GCC 6 runtime > instead of GCC 12. > So I decided that I should just get rid of all *.so, *.a and *.o files in > GCC12 install directory, and later when I build my project I point GCC12 on > GCC6 runtime with -Wl,-L. This is very undefined and unsupported. > > Is there a better way to do this? Maybe I am missing something. > Thanks in advance. The GCC Developer Toolset on RHEL and CentOS solves this properly. The new GCC in the toolset links to libstdc++_nonshared.a which provides all the new symbols not present in the base version of libstdc++.so.6 from the system compiler. The new additions are statically linked, and everything that's already present in the base libstdc++.so.6 gets used from there. Or you can just statically link your whole project.
