Can't I build gcc with multilib support?

Can't I build gcc with multilib support?

[alexandre schenberg]

Hi. I am facing a series of error messages when trying to build it with multilib.

/usr/bin/ld: skipping incompatible /media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/lib32//libgcc_s.so when searching for -lgcc_s
/usr/bin/ld: skipping incompatible /media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/lib32//libgcc_s.so when searching for -lgcc_s
checking for default BUILD_CONFIG... bootstrap-debug
checking for --enable-vtable-verify... no
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.3/libgcc.a when searching for -lgcc
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.3/libgcc.a when searching for -lgcc
/usr/bin/ld: cannot find -lgcc
collect2: ld returned 1 exit status
configure: error: I suspect your system does not have 32-bit developement libraries (libc and headers). If you have them, rerun configure with --enable-multilib. If you do not have them, and want to build a 64-bit-only compiler, rerun configure with --disable-multilib.

This trying to run configure with:

LDFLAGS=-L/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/lib32/ ../configure --prefix=/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4 --disable-checking --enable-languages=c,c++ --enable-multiarch --enable-multlib --with-multilib-list=m32,m64 --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu

If I remove the LDFLAGS above I receive:

/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.3/libgcc.a when searching for -lgcc
/usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.3/libgcc.a when searching for -lgcc
/usr/bin/ld: cannot find -lgcc
collect2: ld returned 1 exit status
configure: error: I suspect your system does not have 32-bit developement libraries (libc and headers). If you have them, rerun configure with --enable-multilib. If you do not have them, and want to build a 64-bit-only compiler, rerun configure with --disable-multilib.

I have Gcc 4.9.4 installed in the dir mentioned above, but have a symbolic link to it on /usr/local/bin and a sym link to libstdc++.so.6.0.20 on /usr/lib32. I removed the system provided Gcc 4.4.3, but apparently it left behind libgcc.a and other stuff. No idea about why it is complaining about incompatible libgcc_s.so.

So, what needs to be done to fix it?

Re: Can't I build gcc with multilib support?

[Jonathan Wakely]

On Fri, 23 Sept 2022 at 02:36, alexandre schenberg via Gcc-help
<gcc-help@gcc.gnu.org> wrote:
>
> Hi. I am facing a series of error messages when trying to build it with multilib.
>
> /usr/bin/ld: skipping incompatible /media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/lib32//libgcc_s.so when searching for -lgcc_s
> /usr/bin/ld: skipping incompatible /media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/lib32//libgcc_s.so when searching for -lgcc_s
> checking for default BUILD_CONFIG... bootstrap-debug
> checking for --enable-vtable-verify... no
> /usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.3/libgcc.a when searching for -lgcc
> /usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.3/libgcc.a when searching for -lgcc
> /usr/bin/ld: cannot find -lgcc
> collect2: ld returned 1 exit status
> configure: error: I suspect your system does not have 32-bit developement libraries (libc and headers). If you have them, rerun configure with --enable-multilib. If you do not have them, and want to build a 64-bit-only compiler, rerun configure with --disable-multilib.
>
> This trying to run configure with:
>
> LDFLAGS=-L/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4/lib32/ ../configure --prefix=/media/34GB/Arquivos-de-Programas-Linux/Gcc-4.9.4 --disable-checking --enable-languages=c,c++ --enable-multiarch --enable-multlib --with-multilib-list=m32,m64 --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
>
> If I remove the LDFLAGS above I receive:
>
> /usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.3/libgcc.a when searching for -lgcc
> /usr/bin/ld: skipping incompatible /usr/lib/gcc/x86_64-linux-gnu/4.4.3/libgcc.a when searching for -lgcc
> /usr/bin/ld: cannot find -lgcc
> collect2: ld returned 1 exit status
> configure: error: I suspect your system does not have 32-bit developement libraries (libc and headers). If you have them, rerun configure with --enable-multilib. If you do not have them, and want to build a 64-bit-only compiler, rerun configure with --disable-multilib.
>
> I have Gcc 4.9.4 installed in the dir mentioned above, but have a symbolic link to it on /usr/local/bin and a sym link to libstdc++.so.6.0.20 on /usr/lib32. I removed the system provided Gcc 4.4.3, but apparently it left behind libgcc.a and other stuff. No idea about why it is complaining about incompatible libgcc_s.so.
>
> So, what needs to be done to fix it?

I'm not really sure what exactly you're doing. Which version of GCC
are you trying to build, 4.9.4? I thought you said you already have
that installed?

If you already have a multilib GCC installed correctly, it should be
able to find its own libgcc.a and libgcc_so.so without any LDFLAGS.

If you aren't using GCC 4.4.3 to build, ld should not be looking in
/usr/lib/gcc/x86_64-linux-gnu/4.4.3/ at all.

So I would recheck your assumptions, something seems strange here.

Why not just reinstall the system provided 4.4.3 and use that to build?

Re:Can't I build gcc with multilib support?

[alexandre schenberg]

Yes, I am trying to build 4.9.4, again. I built it first with multilib support (probably with the help of 32bit libraries installed through the package manager).

However when I try to run any c++ 32bit program (c programs works fine), it ends with segmentation fault. I believe that is due to a conflict  between the 4.9.4 gcc/g++ and libstdc++.so.6.0.20 with the old libraries from gcc 4.4.3 on /usr/lib/...

Finally, I am not sure that only reinstall gcc 4.4.3 would solve it. Reinstall ia32 libs might do it, but first I have a few things to try.

To check Gcc configure.ac and look for the above error messages. Plus, I might created a backup copy of /usr/lib/gcc/x86_64-linux-gnu/4.4.3/ and replace it with /usr/lib/gcc/x86_64-linux-gnu/4.9.4. If that works, I won't even need to do a system wide 4.9.4 install, neither reinstall anything from the package manager (that I would have to uninstall again latter)

Re: Can't I build gcc with multilib support?

[Jonathan Wakely]

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On Sat, 24 Sep 2022, 02:03 alexandre schenberg, <ale.schenberg@yandex.com>
wrote:

> Yes, I am trying to build 4.9.4, again. I built it first with multilib
> support (probably with the help of 32bit libraries installed through the
> package manager).
>


Firstly, why do you even want such an ancient version?


> However when I try to run any c++ 32bit program (c programs works fine),
> it ends with segmentation fault. I believe that is due to a conflict
> between the 4.9.4 gcc/g++ and libstdc++.so.6.0.20 with the old libraries
> from gcc 4.4.3 on /usr/lib/...
>

Secondly, have you tried to debug it? It seems like you're making a guess
and then doing a lot of (maybe unnecessary) work based on that guess.

It should not be possible for any conflict between libstdc++ versions to
cause **any** C++ program to crash. Something is very wrong, you should
figure out what it is, not just install things and remove the system
compiler based on hunches and hope.


> Finally, I am not sure that only reinstall gcc 4.4.3 would solve it.
> Reinstall ia32 libs might do it, but first I have a few things to try.
>
> To check Gcc configure.ac and look for the above error messages. Plus, I
> might created a backup copy of /usr/lib/gcc/x86_64-linux-gnu/4.4.3/ and
> replace it with /usr/lib/gcc/x86_64-linux-gnu/4.9.4.


I don't think that will help. Your GCC 4.9.4 isn't going to just start
looking in random directories. It knows where to find its libraries already.


If that works, I won't even need to do a system wide 4.9.4 install, neither
> reinstall anything from the package manager (that I would have to uninstall
> again latter)
>


Installing and reinstalling some packages doesn't seem so hard. I would go
back to a known-good state using packages from the package manager, then
start from scratch.

If you won't do that, I would figure out why the libraries in
/usr/libx86_64-linux-gnu/4.4.3 are even being considered by the linker.
That's not a standard system path, so GCC 4.9.4 should not be looking in
there.

Compile with -v and -Wl,v -Wl,t to see wht paths are being passed to the
linker, and which files the linker is looking at. Try that when compiling a
C program, and when compiling a C++ program. Check that the 'gcc' nd 'g++'
binaries are consistent. It sounds to me like you might have created some
kind of hybrid of GCC 4.4.2 and 4.9.4!

Re: Can't I build gcc with multilib support?

[Jonathan Wakely]

On Sat, 24 Sept 2022 at 11:18, Jonathan Wakely wrote:
> If you won't do that, I would figure out why the libraries in /usr/libx86_64-linux-gnu/4.4.3 are even being considered by the linker. That's not a standard system path, so GCC 4.9.4 should not be looking in there.
>
> Compile with -v and -Wl,v -Wl,t to see wht paths are being passed to the linker, and which files the linker is looking at. Try that when compiling a C program, and when compiling a C++ program. Check that the 'gcc' nd 'g++' binaries are consistent. It sounds to me like you might have created some kind of hybrid of GCC 4.4.2 and 4.9.4!


And if none of that works, show us **exactly** the configure command
you're using, and the output of 'gcc -v' for all existing GCC
installations on the system, so we can see what's actually happening.
It's hard to debug it from your descriptions so far.