#!/bin/bash
_architectures="x86_64-w64-mingw32 i686-w64-mingw32"
CPU_CORES="$(nproc)"
build_exe () {
local arch=$1
local core_count=$2
pushd build-$arch
CMAKE_INCLUDE_PATH="/usr/"$arch"/include"
echo "CMAKE_INCLUDE_PATH = "${CMAKE_INCLUDE_PATH}
export CMAKE_INCLUDE_PATH
$arch-cmake -G"Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug ..
##$arch-cmake -DCMAKE_BUILD_TYPE=Release ..
make VERBOSE=1 -j$core_count
popd
}
for _arch in ${_architectures}; do
case "$1" in
clean) if [ ! -d build-${_arch} ]; then
echo "build directory does not exist. Terminating script.."
else
rm -rvf build-${_arch}
fi
;;
rebuild) if [ -d build-${_arch} ]; then
rm -rvf build-${_arch}
fi
mkdir -p -v build-${_arch}
## call build function
build_exe ${_arch} ${CPU_CORES}
;;
*) if [ ! -d build-${_arch} ]; then
echo "build directory does not exist. Creating directory.."
mkdir -p -v build-${_arch}
fi
## call build function
build_exe ${_arch} ${CPU_CORES}
;;
esac
done
The preceding script is probably rather intimidating. However, it's just a simple bash script. Just focus to the build_exe() function. That's where the core of the action happens: make is invoked with -j parameter, followed by the number of CPU cores in the system. FYI, the script above is a cross-compilation script which runs on Linux and creates Windows executables. But, the latter fact shouldn't deter you from trying to understand the big picture though ;)The script shows how to obtain the number of CPU cores in bash, i.e. via the nproc command. nproc is part of coreutils in Linux. If you're using other kind of Unix, try to find an equivalent command. Once, the number of CPU cores is known, that number is used as parameter to make. Running make in parallel should cut down the build time quite a bit. In some projects, it could be quite a lot of saving in build time.
Not all projects can benefit from parallel build. However, it's worth it to try modifying your project to use parallel build before discounting it as useless ;-)
