Install GNU GCC on mac - macos

Question

I have recently become frustrated with the new clang compiler included with Xcode 5. I was wondering what the best way to install GNU GCC on OS X would be.
Things to consider:
I don't want to use MacPorts, fink, homebrew or any other third party package manager.
I would like to use the latest GCC, compiled from source, if possible.
I need the existing GCC (hardlink to clang) to remain the default, but to easily be able to use GNU GCC when I need to.
I would like to avoid modifying the code if at all possible.
EDIT: Success! Using GCC 4.9.2 (with GMP 5.1.3, MPFR 3.1.2, MPC 1.0.2, ISL 0.12.2, and CLooG 0.18.1) I succesfully built GCC. Tips to take from here:
Make sure you use ISL and CLooG. Yes, they are optional, but they make a more optimised compiler and I had trouble building without them. Make sure you use ISL 0.12, not the latest version (0.14).
If possible, use the standalone Developer Tools, not XCode. (XCode has some buggy headers, and while I didn't notice any issues building GCC I have had issues with other software (e.g. GPG)).
I recommend putting all your sources in the gcc directory, rather than building and installing separately (it's faster this way)
Make sure you invoke configure with CC=clang CXX=clang++ so GCC knows it isn't being compiled by GCC.
Definitely, definitely, definitely, invoke make with -j8, or otherwise the build will take about 4 hours! (With -j8, it took 1 1/3 hours on my Mid-2012 MBP with 8gb RAM.) (make -j8 means make can build 8 threads simultaneously (4 cores + HT), whereas on a 2-core machine you would run make -j4.)
Hope this helps!

Answer 1

Homebrew now has the GCC package so you can install it with this command:
brew install gcc

Answer 2

The way I do it is:
Download the source for GCC and numerous supporting packages. The instructions are in the gcc-4.x.y/INSTALL/index.html file in the GCC source code, or online at http://gcc.gnu.org/install/.
GNU Multiple Precision Library (GMP) version 4.3.2 (or later) from http://gmplib.org/.
MPFR Library version 2.4.2 (or later) from http://www.mpfr.org/.
MPC Library version 0.8.1 (or later) from http://www.multiprecision.org/.
ISL Library version 0.11.1 from ftp://gcc.gnu.org/pub/gcc/infrastructure/.
CLooG 0.18.0 from ftp://gcc.gnu.org/pub/gcc/infrastructure/.
Use a script to extract the source for GCC and the support libraries into a directory, create the object directory, and run the build.
This is the script I used for GCC 4.8.2:
GCC_VER=gcc-4.8.2
tar -xf ${GCC_VER}.tar.bz2 || exit 1
(
cd ${GCC_VER} || exit
cat <<EOF |
cloog 0.18.0 tar.gz
gmp 5.1.3 tar.xz
isl 0.11.1 tar.bz2
mpc 1.0.1 tar.gz
mpfr 3.1.2 tar.xz
EOF
while read file vrsn extn
do
(
set -x
tar -xf "../$file-$vrsn.$extn" &&
ln -s "$file-$vrsn" "$file"
)
done
)
mkdir ${GCC_VER}-obj
cd ${GCC_VER}-obj
../${GCC_VER}/configure --prefix=$HOME/gcc/gcc-4.8.2
make -j8 bootstrap
When that finishes, run the install too. Then add $HOME/gcc/gcc-4.8.2/bin (the name you specify in --prefix plus /bin) to your PATH ahead of /usr/bin.
With a decent MacBook Pro with a 5400 rpm spinning disk, it takes an hour or two to compile everything (using the -j8 option to make), and requires multiple gigabytes of disk space while compiling. SSD is nice when doing this (definitely faster)!
GCC 4.9.0 was released on 2014-04-22. I've installed it using basically the same process, but with CLooG 0.18.1 and ISL 0.12.2 (required updates) and GMP 5.1.3 (and 6.0.0a), MPC 1.0.2 (or 1.0.1) and MPFR 3.1.2 on Mac OS X 10.9.2 Mavericks and an Ubuntu 12.04 derivative. Beware that the gmp-6.0.0a.tar.xz extracts into directory gmp-6.0.0 (not gmp-6.0.0a as you might expect).
Between 2014 and 2017-09-27, I've built GCC versions 4.9.0, 4.9.1, 5.1.0, 5.2.0, 5.3.0, 6.1.0, 6.2.0, 6.3.0, 7.1.0 with only minor variations in the build script shown below for GCC 7.2.0 on macOS Sierra (10.12). The versions of the auxilliary libraries changed reasonably often.
macOS Sierra and High Sierra
On 2017-08-14, I used a minor variant of the script above to build GCC 7.2.0 on macOS Sierra 10.12 (using XCode 8 as the bootstrap compiler). One change is that CLooG doesn't seem to be needed any more (I stopped adding it with GCC 6.2.0). This is my current script:
#!/bin/bash
#export DYLD_LIBRARY_PATH=$(clnpath $(dirname $(dirname $(which g++)))/lib:$DYLD_LIBRARY_PATH)
unset DYLD_LIBRARY_PATH
TAR=/opt/gnu/bin/tar
VER_NUM=7.2.0
GCC_VER=gcc-${VER_NUM}
TGT_BASE=/opt/gcc
TGT_DIR=${TGT_BASE}/v${VER_NUM}
CC=/usr/bin/clang
CXX=/usr/bin/clang++
extract() {
echo "Extract $1"
$TAR -xf $1
}
if [ ! -d "$GCC_VER" ]
then extract ${GCC_VER}.tar.xz || exit 1
fi
(
cd ${GCC_VER} || exit
nbncl <<EOF |
gmp 6.1.2 tar.lz
isl 0.16.1 tar.bz2
mpc 1.0.3 tar.gz
mpfr 3.1.5 tar.xz
EOF
while read file vrsn extn
do
tarfile="../$file-$vrsn.$extn"
if [ ! -f "$tarfile" ]
then echo "Cannot find $tarfile" >&2; exit 1;
fi
if [ ! -d "$file-$vrsn" ]
then
(
set -x
extract "$tarfile" &&
ln -s "$file-$vrsn" "$file"
) || exit 1
fi
done
)
if [ $? = 0 ]
then
mkdir ${GCC_VER}-obj
cd ${GCC_VER}-obj
../${GCC_VER}/configure --prefix="${TGT_DIR}" \
CC="${CC}" \
CXX="${CXX}"
make -j8 bootstrap
fi
Make sure your version of tar supports all 4 different compressed file formats (.lz, .gz, .xz, .bz2), but since the standard Mac version of tar does that for me, it'll probably work for you too.
On 2017-09-27, I failed to build GCC 7.2.0 on macOS High Sierra 10.13 (using XCode 9 for the bootstrap compiler) using the same script as worked on Sierra 10.12. The immediate error was a missing header <stack>; I'll need to track down whether my XCode 9 installation is correct — or, more accurately, why it isn't correct since <stack> is a standard header in C++98 onwards. There's probably an easy fix; I just haven't spent the time chasing it yet. (Yes, I've run xcode-select --install multiple times; the fact that I had to run it multiple times because of network glitches may be part of the trouble.) (I got GCC 7.2.0 to compile successfully on 2017-12-02; I don't recall what gymnastics — if any — were required to get this to work.)
Time passes; version numbers increase. However, the basic recipe has worked for me with more recent versions of GCC. I have 7.3.0 (installed 2018-01-2), 8.1.0 (installed 2018-05-02), 8.2.0 (installed 2018-07-26), 8.3.0 (installed 2019-03-01) and now 9.1.0 (installed today, 2019-05-03). Each of these versions was built and installed on the current version of macOS at the time, using the current version of XCode for the bootstrap phase (so using macOS 10.14.4 Mojave and XCode 10.2.1 when building GCC 9.1.0)

Answer 3

Use a pre-compiled binary specifically for OS X 10.9.x Mavericks:
→ gcc-4.9
Compiled using source code from the GNU servers.
This contains current versions (4.7 is the stable release) of gfortran
(free, open source, GNU Fortran 95 compiler), gcc (GNU C) and g++ (GNU
C++) compilers that can perform auto-vectorization (i.e. modify code
to take advantage of AltiVec/SSE, automatically) and other
sophisticated optimizations like OpenMP. For more information, see
this webpage.
Download my binaries, and cd to the download folder. Then gunzip
gcc-4.9-bin.tar.gz (if your browser didn't do so already) and then
sudo tar -xvf gcc-4.9-bin.tar -C /. It installs everything in
/usr/local. You can invoke the Fortran 95 compiler by simply typing
gfortran. You will also need to have Apple's XCode Tools installed
from the Mac App Store. With XCode 4 or 5 you will need to download
the command-line tools as an additional step. You will find the option
to download the command-line tools in XCode's Preferences.
On 10.9 Mavericks, you can get the command-line tools by simply typing
xcode-select --install.