Caveat for ugrading gcc in a distribution based on Slackware-14.2?

Didier Spaier · 02-25-2021, 07:42 AM

Hello,

I have gcc version 5.5.0 (genuine Slackware package).

If upgrading to the version in -current (10.2.0) or at least 9.2.0, will I have rebuild libtool after that ?

According to gentoo I would need to also rebuild llvm, clang and wxGTK3 (installed in Slint). Others that come to mind?

On the other hand, do I need to first upgrade other components of the system before upgrading gcc?

Thanks for any clue.

PS The reason I consider upgrading is that some software need or will soon need a more recent GCC

BrunoLafleur · 02-25-2021, 07:50 AM

Quote:

Originally Posted by Didier Spaier

Hello,

I have gcc version 5.5.0 (genuine Slackware package).

If upgrading to the version in -current (10.2.0) or at least 9.2.0, will I have rebuild libtool after that ?

According to gentoo I would need to also rebuild llvm, clang and wxGTK3 (installed in Slint). Others that come to mind?

On the other hand, do I need to first upgrade other components of the system before upgrading gcc?

Thanks for any clue.

PS The reason I consider upgrading is that some software need or will soon need a more recent GCC

I suppose you will recompile gcc. If so I don't think you need to upgrade any other libraries. I have already compile gcc form scratch for cross-compilers and you can have a new gcc and (very) old libs (even glibc).

For other packages which were compiled with another version of gcc, the libs libgcc_s.so libstdc++.so of that version should be kept alongside the new ones.

Didier Spaier · 02-25-2021, 08:05 AM

Thanks. Indeed will I recompile (I do that already for the kernels). That means that I will need to also rebuild aaa_elflibs that also ships these libraries. And I will of course keep the /usr/lib64/*.la files else a lot of installed software will become unhappy.

drumz · 02-25-2021, 08:29 AM

Quote:

Originally Posted by Didier Spaier

PS The reason I consider upgrading is that some software need or will soon need a more recent GCC

I would recommend (and is what I do) installing a newer GCC into /opt. I do this for MATLAB.

No, this isn't a proper Slackware package, but it's installed in /opt and I assume GCC is well-behaved

do_build.sh: (I tweak for each different version of GCC, using Pat's SlackBuilds as guides)

Code:

#!/bin/sh

srcdir=../gcc-8.4.0
destdir=/opt/gcc-8.4.0

SLKCFLAGS="-O2 -fPIC"
LIBDIRSUFFIX="64"
LIB_ARCH=amd64

TARGET=x86_64-slackware-linux

NUMJOBS=" -j 8 "

CFLAGS="$SLKCFLAGS" \
CXXFLAGS="$SLKCFLAGS" \
"$srcdir/configure" \
  --prefix=$destdir \
  --libdir=$destdir/lib$LIBDIRSUFFIX \
  --enable-bootstrap \
  --enable-languages=ada,brig,c,c++,fortran,lto,objc,obj-c++ \
  --enable-threads=posix \
  --enable-checking=release \
  --enable-objc-gc \
  --with-system-zlib \
  --enable-libstdcxx-dual-abi \
  --with-default-libstdcxx-abi=gcc4-compatible \
  --with-python-dir=/lib$LIBDIRSUFFIX/python2.7/site-packages \
  --disable-libunwind-exceptions \
  --enable-__cxa_atexit \
  --enable-libssp \
  --enable-lto \
  --disable-install-libiberty \
  --with-gnu-ld \
  --verbose \
  --with-arch-directory=$LIB_ARCH \
  --disable-gtktest \
  --disable-multilib \
  --target=${TARGET} \
  --build=${TARGET} \
  --host=${TARGET} || exit 1

make $NUMJOBS bootstrap;
( cd gcc || exit
  make $NUMJOBS gnatlib GNATLIBCFLAGS="$SLKCFLAGS"

  CFLAGS="$SLKCFLAGS" \
	  CXXFLAGS="$SLKCFLAGS" \
	  make $NUMJOBS gnattools
)
make info

make install || exit 1

Then in my startup.m for MATLAB I have:

Code:

% Add GCC to PATH
if contains(ver_str, 'R2016b') || contains(ver_str, 'R2017a') || ...
        contains(ver_str, 'R2017b')
    if exist('/opt/gcc-4.9.4/bin', 'dir')
        setenv('PATH', ['/opt/gcc-4.9.4/bin:' getenv('PATH')]);
    end
end
if contains(ver_str, 'R2018a') || contains(ver_str, 'R2018b') || ...
        contains(ver_str, 'R2019a') || contains(ver_str, 'R2019b') || ...
        contains(ver_str, 'R2020a')
    if exist('/opt/gcc-6.3.0/bin', 'dir')
        setenv('PATH', ['/opt/gcc-6.3.0/bin:' getenv('PATH')]);
    end
end
if contains(ver_str, 'R2020b')
    if exist('/opt/gcc-8.4.0/bin', 'dir')
        setenv('PATH', ['/opt/gcc-8.4.0/bin:' getenv('PATH')]);
    end
end

So when compiling things in MATLAB it will automagically pick up the correct GCC version.

Didier Spaier · 02-25-2021, 09:01 AM

Thanks drumz. However it's for Slint not for me, so I can't handle things that way.