GCC & binutils build - C compiler cannot create executables - c++

Question

I'm trying to build gcc-5.3 and binutils-2.26. I've done it like this:
mkdir gcc; cd gcc
wget http://path/to/gcc-5.3.0.tar.bz2
wget http://path/to/binutils-2.26.tar.bz2
tar xf gcc-5.3.0.tar.bz2
tar xf binutils-2.26.tar.bz2
cd gcc-5.3.0
contrib/download_prerequisites
for file in ../binutils-2.26/*; do ln -s "${file}"; done
cd ..
mkdir build
mkdir dist
cd build
../gcc-5.3.0/configure --prefix=/home/teamcity/gcc/dist --disable-multilib --with-system-zlib --enable-languages=c,c++,fortran --program-suffix=-mine
make
This appears to build the first stage executables okay; prev-gas, prev-gcc, prev-ld are all present with plausible-looking executables in them. But the next stage fails:
Configuring stage 2 in ./intl
configure: loading cache ./config.cache
checking whether make sets $(MAKE)... yes
checking for a BSD-compatible install... /usr/bin/install -c
checking whether NLS is requested... yes
checking for msgfmt... /usr/bin/msgfmt
checking for gmsgfmt... /usr/bin/msgfmt
checking for xgettext... /usr/bin/xgettext
checking for msgmerge... /usr/bin/msgmerge
checking for x86_64-unknown-linux-gnu-gcc... /home/teamcity/gcc/build/./prev-gcc/xgcc -B/home/teamcity/gcc/build/./prev-gcc/ -B/home/teamcity/gcc/dist/x86_64-unknown-linux-gnu/bin/ -B/home/teamcity/gcc/dist/x86_64-unknown-linux-gnu/bin/ -B/home/teamcity/gcc/dist/x86_64-unknown-linux-gnu/lib/ -isystem /home/teamcity/gcc/dist/x86_64-unknown-linux-gnu/include -isystem /home/teamcity/gcc/dist/x86_64-unknown-linux-gnu/sys-include -L/home/teamcity/gcc/build/./ld
checking for C compiler default output file name...
configure: error: in `/home/teamcity/gcc/build/intl':
configure: error: C compiler cannot create executables
See `config.log' for more details.
The relevant bit of config.log appears to be this:
configure:2978: checking for C compiler default output file name
configure:3000: /home/teamcity/gcc/build/./prev-gcc/xgcc -B/home/teamcity/gcc/build/./prev-gcc/ -B/home/teamcity/gcc/dist/x86_64-unknown-linux-gnu/bin/ -B/home/teamcity/gcc/dist/x86_64-unkn
own-linux-gnu/bin/ -B/home/teamcity/gcc/dist/x86_64-unknown-linux-gnu/lib/ -isystem /home/teamcity/gcc/dist/x86_64-unknown-linux-gnu/include -isystem /home/teamcity/gcc/dist/x86_64-unknown-l
inux-gnu/sys-include -L/home/teamcity/gcc/build/./ld -g -O2 -gtoggle -static-libstdc++ -static-libgcc conftest.c >&5
/home/teamcity/gcc/build/./prev-gcc/as: 106: exec: /home/teamcity/gcc/build/./gas/as-new: not found
This looks like prev-gcc's as is expecting to find gas/as-new, when actually it's prev-gas/as-new.
Is there some workaround for this? Is it safe to just ln -s prev-gas gas? I'd sort of expect that to cause problems later on. Is it not possible to build these two versions of gcc and binutils together?

Answer 1

This is my edited answer after trying it on my own on an Ubuntu 14.04 Azure VM.
The following approach worked for me:
Build and install binutils 2.26; for the purposes of this discussion,
let's say it's installed in /opt/gcc-5.3.0.
Configure gcc-5.3.0 in a build directory using /root/objdir/../gcc-5.3.0/configure --prefix=/opt/gcc-5.3.0
--enable-languages=c,c++ --disable-multilib --with-ld=/opt/gcc-5.3.0/bin/ld --with-as=/opt/gcc-5.3.0/bin/as assuming gcc-5.3.0 and the build directory, objdir, are at the same
level.
Do make followed by make install in the objdir build directory.
To verify that the ld used by the newly-built gcc is the one from the new binutils:
/opt/gcc-5.3.0/bin/gcc -print-prog-name=ld
The output should be, in this example:
/opt/gcc-5.3.0/bin/ld
Another test: rename the system ld, in my case /usr/bin/ld; the newly-built gcc should still work.
Of course, this applies to both ld and as.
Setting AS and LD environment variables to point to the newly-built binaries from the binutils package did not work: the -print-prog-name=... still showed default tools, and removing/renaming the default tools caused gcc to fail.
Thus the best way of accomplishing this is to build binutils first and then use the --with-ld and --with-as options to configure. If you also want to ensure that the newly-built binutils are used to build GCC, you may want to put them in the PATH before the system-provided tools, or you can even rename the system-provided tools to keep them out of the picture.
Thank you for checking with another mailing list to verify that building GCC and binutils together doesn't work unless they are pulled from the source control, I guess that option is not applicable when using downloaded tarballs. Overall this was an interesting exercise.