How to debug GCC/LD linking process for STL/C++

Using GCC's -v and -Wl,-v options will show you the linker commands (and version info of the linker) being used.

Which version of GCC are you using? I made some changes for GCC 4.6 (see PR 44647 and PR 43863) to reduce code size to help embedded systems. There's still an outstanding enhancement request (PR 43852) to allow disabling the inclusion of the IO symbols you're seeing - some of them come from the verbose terminate handler, which prints a message when the process is terminated with an active exception. If you're not using execptions then some of that code is useless to you.

The problem is not about the STL, it is about the Standard library.

The STL itself is pure (in a way), but the Standard Library also includes all those streams packages and it seems that you also managed to pull in the libc as well...

The problem is that the Standard Library has never been meant to be picked apart, so there might not have been much concern into re-using stuff from the C Standard Library...

You should first try to identify which files are pulled in when you compile (using strace for example), this way you can verify that you only ever use header-only files.

Then you can try and remove the linking that occurs. There are options to pass to gcc to precise that you would like a standard library-free build, something like --nostdlib for example, however I am not well versed enough in those to instruct you exactly here.