Makefile.common

# This is a cross-platform Makefile.
# It is written to work exactly the same on Linux, OSX, and Windows,
# with CMake and Conan as its only requirements.
# In addition to acting as a build system,
# CMake is used as a cross-platform coreutils,
# with subcommands for, e.g., mkdir, touch, and rm.

ifeq ($(OS),Windows_NT)
	SHELL := powershell.exe
	.SHELLFLAGS :=
	EXE := .exe
	NPROC := $(shell $$env:NUMBER_OF_PROCESSORS)
	generator ?= Visual Studio 16 2019
	multi ?= true
else
	SHELL := /bin/bash
	.SHELLFLAGS := -o pipefail -c
	ifeq ($(shell uname -s),Darwin)
		NPROC := $(shell sysctl -n hw.logicalcpu)
	else
		NPROC := $(shell nproc)
	endif
	generator ?= Ninja
	multi ?=
endif

flavor ?= Release
shared ?= OFF
options ?=
executable ?= true

source_dir := ${CURDIR}
build_dir ?= ${source_dir}/.build
install_dir ?= ${source_dir}/../.install

CMAKE ?= cmake
CTEST ?= ctest
CONAN ?= conan

.DEFAULT_GOAL := test

${build_dir} :
	${CMAKE} -E make_directory $@

conanfile := $(wildcard conanfile.*)

conan_toolchain := ${build_dir}/conan_toolchain.cmake

# Windows will not tolerate line breaks in a command.
${conan_toolchain} : ${conanfile} | ${build_dir}
	${CMAKE} -E chdir ${build_dir} ${CONAN} install ${source_dir} --build missing -s build_type=${flavor} --profile:build default --profile:host default --output-folder .

conan : ${conan_toolchain}

toolchain := $(if ${conanfile},${conan_toolchain},)

cache := ${build_dir}/CMakeCache.txt

${cache} : ${toolchain} Makefile | ${build_dir}
	${CMAKE} -E chdir ${build_dir} ${CMAKE} -G "${generator}" -DCMAKE_TOOLCHAIN_FILE="${toolchain}" -DCMAKE_INSTALL_PREFIX="${install_dir}" -DCMAKE_PREFIX_PATH="${install_dir}" $(if ${multi},,-DCMAKE_BUILD_TYPE=${flavor}) -DBUILD_SHARED_LIBS=${shared} ${options} ${source_dir} 2>&1 | tee ${build_dir}/configure.log
	${CMAKE} -E touch $@

configure : ${cache}

built_executable := ${build_dir}/output/${flavor}/bin/${executable}${EXE}

${built_executable} : ${cache} $(wildcard ${source_dir}/src/*.cpp)
	${CMAKE} -E time ${CMAKE} --build ${build_dir} --verbose $(if ${multi},--config ${flavor}) --parallel ${NPROC} --target $(if ${multi},ALL_BUILD,all) 2>&1 | tee ${build_dir}/build.log
	${SHELL} ${.SHELLFLAGS} "ls -l '$@'"
	${SHELL} ${.SHELLFLAGS} "ls -l '$<'"
	${CMAKE} -E touch $@

build : ${built_executable}

exe :
	${built_executable}

force :
	${CMAKE} -E touch ${cache}
	${MAKE} build

test : ${cache}
	${CMAKE} -E time ${CMAKE} --build ${build_dir} --verbose $(if ${multi},--config ${flavor}) --parallel ${NPROC}  --target $(if ${multi},RUN_TESTS,test) 2>&1 | tee ${build_dir}/test.log

ctest : ${cache}
	${CMAKE} -E chdir ${build_dir} ${CTEST} --verbose $(if ${multi},--build-config ${flavor}) --parallel ${NPROC}

installed_executable := ${install_dir}/bin/${executable}${EXE}

# The --install option was added in CMake 3.15.
${installed_executable} : ${cache}
	${CMAKE} -E time ${CMAKE} --build ${build_dir} --verbose --target install $(if ${multi},--config ${flavor})
	${SHELL} ${.SHELLFLAGS} "ls -l '$@'"
	${SHELL} ${.SHELLFLAGS} "ls -l '$<'"
	${CMAKE} -E touch $@

install : ${installed_executable}

installed :
	${installed_executable}

clean :
	${CMAKE} -E rm -rf ${build_dir}

uninstall :
	${CMAKE} -E rm -rf ${install_dir}