a single Makefile bootstrap for a simple C++ project with cmake

README.md

a pre-make for CMake based projects

This is my simple pre-make script for bootstrapping CMake for a small project

Usage

Make a new cpp project directory and download this Makefile to your new project workspace via curl using the following commands :

$ mkdir my-new-project
$ cd my-new-project
$ curl -sSL \
   -o Makefile \
   --no-clobber \
   https://gist.githubusercontent.com/brianonn/f10eaf000a4358478afb5b3cc8925b1d/raw/Makefile
$ make

When building with the Makefile it will create the executable in build/main.

I have the following alias defined as well. This will add a new alias cppboot and make it easier to just invoke cppboot in a new directory whenever you want to bootstrap a new cpp project on Linux:

alias cppboot='[ ! -e Makefile ] && curl -sSL -o Makefile https://gist.githubusercontent.com/brianonn/f10eaf000a4358478afb5b3cc8925b1d/raw/Makefile  || echo "Makefile already exists in the current directory"'

After bootstrapping with the Makefile you can remove the Makefile and replace it with build.sh for a more advanced build environment with Debug and Release and Test support. The file build.sh file is not always needed, but can be helpful for these more complex builds. Download build.sh with curl too, if you want to use it.

$ rm -rf build
$ rm -rf Makefile
$ curl -sSL \
   -o build.sh \
   --no-clobber \
   https://gist.githubusercontent.com/brianonn/f10eaf000a4358478afb5b3cc8925b1d/raw/build.sh
$ chmod 755 build.sh
$ ./build.sh

You can get help with ./build.sh -h

When building with build.sh it will create the executables in build/Debug/main and build/Release/main

build/
├── Debug
│   ├── CMakeCache.txt
│   ├── CMakeFiles
│   ├── cmake_install.cmake
│   ├── main
│   └── Makefile
├── Release
│   ├── CMakeCache.txt
│   ├── CMakeFiles
│   ├── cmake_install.cmake
│   ├── main
│   └── Makefile
└── _THIS_DIR_CAN_BE_REMOVED_

See also

premake5 - A more comprehensive and cross-platform/cross-architecture pre-make system.

build.sh

#!/bin/bash

## This build.sh file is also helpful

cmake_build_dir="build"
RM="/bin/rm -rf"

# files generated by cmake
cmake_generated=()
cmake_generated+=("${cmake_build_dir}")
cmake_generated+=(Makefile generated)
cmake_generated+=(CMakeCache.txt *.cmake DartConfiguration.tcl Testing generated)

# create a gitignore file in the directory passed in $1
function gitignore() {
    local gitignore="$1/.gitignore"
    if [[ ! -f ${gitignore} ]]; then
    (
        echo "# Autogenerated by build.sh"
        echo "#"
        echo "# ignore this directory and eveything inside it"
        echo "*"
    ) >> ${gitignore}
    fi
}

# first turn long args into short args for getopts to use
args=()
while [ $# -gt 0 ]; do
    case "$1" in
        --clean)    args+=(-c)   ;;
        --verbose)  args+=(-v)   ;;
        --test)     args+=(-t)   ;;
        --help)     args+=(-h)   ;;
        --)         args+=("$@") ;;
        *)          args+=("$1") ;;
    esac
    shift
done

# set the new args
set -- "${args[@]}"

# now use getopts which doesn't support long args
testing=0
clean=0
verbose=""
while getopts "hcvt" OPT; do
    case "$OPT" in
        t) testing=1 ;;
        c) clean=1
           echo "Cleaning ${cmake_build_dir} dir ..."
           echo ${RM} "${cmake_generated[@]}"
           ${RM} "${cmake_generated[@]}"
           exit 0
           ;;
        v) verbose="-v" ;;
        h) echo "Usage: build.sh [-h | --help] [-v | --verbose] [-t | --test] [ -c | --clean]"
           exit 0
           ;;
        \?) exit 1
            ;;
    esac
done

mkdir -p ${cmake_build_dir}
touch ${cmake_build_dir}/_THIS_DIR_CAN_BE_REMOVED_
gitignore ${cmake_build_dir}

cmake -S . -B ${cmake_build_dir}/Debug -D CMAKE_BUILD_TYPE=Debug
cmake --build ${cmake_build_dir}/Debug $verbose

cmake -S . -B ${cmake_build_dir}/Release -D CMAKE_BUILD_TYPE=Release
cmake --build ${cmake_build_dir}/Release $verbose

if [ $testing -eq 1 ]; then
    for config in Debug Release; do
        echo
        echo "--- TEST::BEGIN (${config}) ---"
        echo
        ctest --test-dir ${cmake_build_dir}/${config}/
        echo
        echo "--- TEST::END ---"
        echo
    done
fi

Makefile

PROJECT = main
MAINCPP = main.cpp
CMAKELISTS = CMakeLists.txt

.PHONY: clean run bootstrap all

all: build/$(PROJECT)

build/$(PROJECT): $(MAINCPP) build
	$(MAKE) -C build

build: $(CMAKELISTS)
	@ rm -rf build
	cmake -B build

run: build/$(PROJECT)
	build/$(PROJECT)

clean:
	rm -rf build

$(MAINCPP) $(CMAKELISTS):
	rm -f $(CMAKELISTS) $(MAINCPP)
	@ echo "cmake_minimum_required(VERSION 3.14)" >> $(CMAKELISTS)
	@ echo "project(main)" >> $(CMAKELISTS)
	@ echo "set(CMAKE_CXX_STANDARD 17)" >> $(CMAKELISTS)
	@ echo "add_executable(main main.cpp)" >> $(CMAKELISTS)
	@ echo "#include <iostream>" >> $(MAINCPP)
	@ echo "" >> $(MAINCPP)
	@ echo "int main(void) {" >> $(MAINCPP)
	@ echo "    std::cout << \"Running main()...\" << std::endl;" >> $(MAINCPP)
	@ echo "    // add your code here" >> $(MAINCPP)
	@ echo "    std::cout << \"Done!\" << std::endl;" >> $(MAINCPP)
	@ echo "    return 0;" >> $(MAINCPP)
	@ echo "}" >> $(MAINCPP)