#!/bin/bash

# From here: https://solarianprogrammer.com/2017/05/21/compiling-gcc-macos/

# This will force you to enter your password so it won't prompt later
sudo ls > /dev/null

# Make sure the directory/file permissions are correct
umask 0022

# Change this if you want to install somewhere else
INSTALL_DIR=/usr/local/gcc-7.1

# get the number of cores (for make -j)
eval getconf _NPROCESSORS_ONLN > /dev/null
result=$?
if [[ $result -eq 0 ]]; then 
	NPROCS=`getconf _NPROCESSORS_ONLN`
else
	NPROCS=4
fi

# uncomment the line below to force the number of cores to use
#NPROCS=4

# install some necessary command line tools (Mac only)
# this should really be done prior to running this script
#xcode-select --install

###############################################################################
# extract, build, and install gmp
tar -xjvf gmp-6.1.2.tar.bz2
cd gmp*
mkdir build
cd build
../configure --prefix=${INSTALL_DIR} --enable-cxx
make -j$(NPROCS)
sudo make install

# go back to the root of the build dir
cd ..
cd ..

###############################################################################
# extract, build, and install mpfr
tar -xjvf mpfr-3.1.5.tar.bz2
cd mpfr*
mkdir build
cd build
../configure --prefix=${INSTALL_DIR} --with-gmp=${INSTALL_DIR}
make -j${NPROCS}
sudo make install

# go back to root of the build dir
cd ..
cd ..

###############################################################################
# extract, build, and install mpc
tar -xzvf mpc-1.0.3.tar.gz
cd mpc*
mkdir build
cd build
../configure --prefix=${INSTALL_DIR} --with-gmp=${INSTALL_DIR} --with-mpfr=${INSTALL_DIR}
make -j${NPROCS}
sudo make install

# go back to root of the build dir
cd ..
cd ..

###############################################################################
# extract, build, and install isl
tar -xjvf isl-0.16.1.tar.bz2
cd isl*
mkdir build
cd build
../configure --prefix=${INSTALL_DIR} --with-gmp-prefix=${INSTALL_DIR}
make -j${NPROCS}
sudo make install

# go back to root of the build dir
cd ..
cd ..

###############################################################################
# extract, build, and install gcc/g++ (This could take a while)
tar -xjvf gcc-7.1.0.tar.bz2
cd gcc*
mkdir build
cd build

# removed fortran from the list of compilers to build, only building c and c++
../configure --prefix=${INSTALL_DIR} --enable-checking=release --with-gmp=${INSTALL_DIR} --with-mpfr=${INSTALL_DIR} --with-mpc=${INSTALL_DIR} --enable-languages=c,c++ --with-isl=${INSTALL_DIR} --program-suffix=-7.1
time make -j${NPROCS}
sudo make install

# go back to root
cd ..
cd ..

###############################################################################
# Show the files and the version to make sure it worked.
ls -l ${INSTALL_DIR}/bin
${INSTALL_DIR}/bin/gcc-7.1 --version
export PATH=${INSTALL_DIR}/bin:$PATH

# compile a test program to verify the installation
g++-7.1 main.cpp -std=c++14 -o main
./main