[Bug c++/61652] New: Option --enable-libstdcxx-debug doesn't pass debug options to libstdc++.so

["yuri at tsoft dot com" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61652

            Bug ID: 61652
           Summary: Option --enable-libstdcxx-debug doesn't pass debug
                    options to libstdc++.so
           Product: gcc
           Version: 4.8.2
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: yuri at tsoft dot com

Based on documentation here
https://gcc.gnu.org/onlinedocs/libstdc++/manual/debug.html I configured gcc to
build a debug version of libstdc++.so:
$ ../src/configure --prefix=/opt/gcc/4.8.2/ --enable-libstdcxx-debug
--enable-libstdcxx-debug-flags='-g3 -O0'
$ gmake

It did build another version of libstdc++.so with different size under
lib/debug/, but both of them have local variables optimized away.

I am interested in ../src/libstdc++-v3/libsupc++/dyncast.cc, touching it and
rebuilding shows that -O0 hasn't been passed to the compile command, and it
builds with -O2.

Building gcc-4.8.2 on FreeBSD-10