Re: building gcc 4.0.2 with gcc 4.6.3: version `GCC_4.2.0' not found

[Ian Lance Taylor <iant at google dot com>]

On Tue, Aug 28, 2012 at 10:30 AM, Ilya Basin <basinilya@gmail.com> wrote:
> Hi list! I can't build older gcc on archlinux 64.
>
> I want to build gcc with bounds checking patches. Bu first I want to
> test the build without the patches.
>
> $ ~/gcc-4.0.2/configure --disable-multilib
> $ make BOOT_CFLAGS="-O2" STAGE1_CFLAGS="-O2" CFLAGS="-O2" bootstrap
> ...
> checking for C compiler default output file name... configure: error: C compiler cannot create executables
> See `config.log' for more details.
> make[1]: *** [configure-fixincludes] Error 1
>
> $ less fixincludes/config.log
> configure:1782: gcc -O2   conftest.c  >&5
> /usr/lib/gcc/x86_64-unknown-linux-gnu/4.6.3/cc1: /home/il/build_4.0.2_dir/gcc/libgcc_s.so.1: version `GCC_4.2.0' not found (required by /usr/lib/libstdc++.so.6)

Somehow when your existing 4.6.3 GCC runs the dynamic linker is
picking up your newly built libgcc_s.so.1.  That fails, because your
system libstdc++.so.6 requires a version of libgcc_s.so.1 newer than
the one in 4.0.2.

It is strange that your existing 4.6.3 GCC is dynamically linked
against libstdc++.so.6.  That does not normally happen.  Normally when
GCC is built using a C++ compiler it links statically against
libstdc++.a.

Anyhow, I think this is happening because the top level Makefile is
setting LD_LIBRARY_PATH.  And I think in GCC 4.0.2 that happens by
default, but you can turn it off by using --disable-shared when you
run configure.  So unless you badly need the GCC 4.0.2 dynamic
libraries for some reason, I recommend using --disable-shared.

Otherwise hack the top level Makefile.in to stop it from setting
LD_LIBRARY_PATH.  In that file it's known as RPATH_ENVVAR.

Ian