Makefile

################################################################################
#### Variables and settings
################################################################################

# Executable name
EXEC = TrainEngine

# Build, bin, assets, and install directories (bin and build root directories are kept for clean)
BUILD_DIR_ROOT = build
BIN_DIR_ROOT = bin
ASSETS_DIR = assets
ASSETS_OS_DIR := $(ASSETS_DIR)_os
INSTALL_DIR := ~/Desktop/$(EXEC)

# Sources (searches recursively inside the source directory)
SRC_DIR = src
SRCS := $(sort $(shell find $(SRC_DIR) -name '*.cpp'))

# Includes
INCLUDE_DIR = include
SFML_DIR = libs/SFML-2.4.2
INCLUDES := -I$(INCLUDE_DIR) -idirafter $(SFML_DIR)/include

# C preprocessor settings
CPPFLAGS = $(INCLUDES) -MMD -MP

# C++ compiler settings
CXX = g++
CXXFLAGS = -std=c++14
WARNINGS = -Wall -Wpedantic -Wextra -Wcast-align -Wduplicated-cond -Wlogical-op -Wmissing-declarations\
		-Wmissing-include-dirs -Wno-aggressive-loop-optimizations -Wnon-virtual-dtor -Wredundant-decls\
		-Wshadow -Wsuggest-override -Wundef -Wunreachable-code -Wuseless-cast -Wzero-as-null-pointer-constant\
		-Wno-unused-parameter

# Linker flags
LDFLAGS =

# Libraries to link
LDLIBS =

# Xcode project path
XCODE_PROJ := proj/xcode/$(EXEC).xcodeproj

# SFML libraries
SFML_GRAPHICS_LIBS = sfml-graphics
SFML_WINDOW_LIBS = sfml-window
SFML_AUDIO_LIBS = sfml-audio
SFML_NETWORK_LIBS = sfml-network
SFML_SYSTEM_LIBS = sfml-system

# Target OS detection
ifeq ($(OS),Windows_NT) # OS is a preexisting environment variable on Windows
	OS = windows
else
	UNAME := $(shell uname -s)
	ifeq ($(UNAME),Darwin)
		ifeq ($(ios),1)
			OS = ios
		else
			OS = macos
		endif
	else ifeq ($(UNAME),Linux)
		OS = linux
	else
    	$(error OS not supported by this Makefile)
	endif
endif

# OS-specific settings
ifeq ($(OS),windows)
	# Link libgcc and libstdc++ statically on Windows
	LDFLAGS += -static-libgcc -static-libstdc++

	# Disable console output on release builds
	ifeq ($(release),1)
		LDFLAGS += -mwindows
	endif

	# Link -s SFML libs in release, and -s-d in debug
	ifeq ($(release),1)
		SFML_LIBS_SUFFIX = -s
	else
		SFML_LIBS_SUFFIX = -s-d
	endif

	# Edit SFML lib names with suffix
	SFML_GRAPHICS_LIBS := $(SFML_GRAPHICS_LIBS)$(SFML_LIBS_SUFFIX)
	SFML_WINDOW_LIBS := $(SFML_WINDOW_LIBS)$(SFML_LIBS_SUFFIX)
	SFML_AUDIO_LIBS := $(SFML_AUDIO_LIBS)$(SFML_LIBS_SUFFIX)
	SFML_NETWORK_LIBS := $(SFML_NETWORK_LIBS)$(SFML_LIBS_SUFFIX)
	SFML_SYSTEM_LIBS := $(SFML_SYSTEM_LIBS)$(SFML_LIBS_SUFFIX)

	# Link SFML statically and add the dependencies for statically-linked SFML libraries
	CPPFLAGS += -DSFML_STATIC
	SFML_GRAPHICS_LIBS += freetype jpeg
	SFML_WINDOW_LIBS += opengl32 gdi32
	SFML_AUDIO_LIBS += openal32 flac vorbisenc vorbisfile vorbis ogg
	SFML_NETWORK_LIBS += ws2_32
	SFML_SYSTEM_LIBS += winmm

	# Windows 32- and 64-bit common settings
	INCLUDES +=
	LDFLAGS +=
	LDLIBS +=

	ifeq ($(win32),1)
		# Windows 32-bit settings
		INCLUDES +=
		LDFLAGS += -L$(SFML_DIR)/lib/windows-gcc-6.1.0-mingw-32-bit
		LDLIBS +=
	else
		# Windows 64-bit settings
		INCLUDES +=
		LDFLAGS += -L$(SFML_DIR)/lib/windows-gcc-6.1.0-mingw-64-bit
		LDLIBS +=
	endif
else ifeq ($(OS),macos)
	# macOS-specific settings
	EXEC := $(EXEC).app
	XCODE_SCHEME = macOS
	INCLUDES +=
	LDFLAGS += -L/Library/Frameworks
	LDLIBS +=
else ifeq ($(OS),ios)
	# iOS-specific settings
	EXEC := $(EXEC).app
	XCODE_SCHEME = iOS
	INCLUDES +=
	LDFLAGS += -L$(SFML_DIR)/lib/ios
	LDLIBS +=
else ifeq ($(OS),linux)
	# Linux-specific settings
	INCLUDES +=
	LDFLAGS +=
	LDLIBS +=
endif

# Add SFML to linked libraries
SFML_GRAPHICS_LIBS := $(addprefix -l,$(SFML_GRAPHICS_LIBS))
SFML_WINDOW_LIBS := $(addprefix -l,$(SFML_WINDOW_LIBS))
SFML_AUDIO_LIBS := $(addprefix -l,$(SFML_AUDIO_LIBS))
SFML_NETWORK_LIBS := $(addprefix -l,$(SFML_NETWORK_LIBS))
SFML_SYSTEM_LIBS := $(addprefix -l,$(SFML_SYSTEM_LIBS))

LDLIBS += $(SFML_GRAPHICS_LIBS) $(SFML_WINDOW_LIBS) $(SFML_AUDIO_LIBS) $(SFML_NETWORK_LIBS) $(SFML_SYSTEM_LIBS)

################################################################################
#### Final setup
################################################################################

# Windows-specific default settings
ifeq ($(OS),windows)
	# Add .exe extension to executable
	EXEC := $(EXEC).exe

	ifeq ($(win32),1)
		# Compile for 32-bit
		CXXFLAGS += -m32
	else
		# Compile for 64-bit
		CXXFLAGS += -m64
	endif
endif

# OS-specific build, bin, and assets directories
BUILD_DIR := $(BUILD_DIR_ROOT)/make_$(OS)
BIN_DIR := $(BIN_DIR_ROOT)/$(OS)
ASSETS_OS_DIR := $(ASSETS_OS_DIR)/$(OS)
ifeq ($(OS),windows)
	# Windows 32-bit
	ifeq ($(win32),1)
		BUILD_DIR := $(BUILD_DIR)32
		BIN_DIR := $(BIN_DIR)32
		ASSETS_OS_DIR := $(ASSETS_OS_DIR)32
	# Windows 64-bit
	else
		BUILD_DIR := $(BUILD_DIR)64
		BIN_DIR := $(BIN_DIR)64
		ASSETS_OS_DIR := $(ASSETS_OS_DIR)64
	endif
endif

# Debug (default) and release modes settings
ifeq ($(release),1)
	BUILD_DIR := $(BUILD_DIR)/release
	BIN_DIR := $(BIN_DIR)/release
	CXXFLAGS += -O3
	CPPFLAGS += -DNDEBUG
else
	BUILD_DIR := $(BUILD_DIR)/debug
	BIN_DIR := $(BIN_DIR)/debug
	CXXFLAGS += -O0 -g
endif

# Objects and dependencies
OBJS := $(SRCS:$(SRC_DIR)/%.cpp=$(BUILD_DIR)/%.o)
DEPS := $(OBJS:.o=.d)
COMPDBS := $(OBJS:.o=.json)

# Include program info and icon on Windows
ifeq ($(OS),windows)
	OBJS += $(BUILD_DIR)/resource.res
endif

# All files (sources and headers)
FILES := $(shell find $(SRC_DIR) $(INCLUDE_DIR) -name '*.cpp' -o -name '*.h' -o -name '*.hpp' -o -name '*.inl')

################################################################################
#### Targets
################################################################################

.PHONY: all
ifneq (,$(filter $(OS),macos ios)) # Build using xcodebuild if platform is macOS or iOS
all: xcodebuild
else # Build normally if platform is neither macOS nor iOS
all: $(BIN_DIR)/$(EXEC)
endif

# Build executable
$(BIN_DIR)/$(EXEC): $(OBJS)
	@echo "Building executable: $@"
	@mkdir -p $(@D)
	@$(CXX) $(LDFLAGS) $^ $(LDLIBS) -o $@

# Compile C++ source files
$(BUILD_DIR)/%.o: $(SRC_DIR)/%.cpp
	@echo "Compiling: $<"
	@mkdir -p $(@D)
	@$(CXX) $(CPPFLAGS) $(CXXFLAGS) $(WARNINGS) -c $< -o $@

# Add resource file to Windows executable
$(BUILD_DIR)/%.res: assets/metadata/%.rc
	@echo "Compiling Windows resource file"
	@windres $< -O coff -o $@

# Build Xcode project using xcodebuild
.PHONY: xcodebuild
xcodebuild:
	@echo "Building project: $(XCODE_PROJ)"
	@xcodebuild -quiet -project $(XCODE_PROJ) -scheme $(XCODE_SCHEME) build

# Include automatically generated dependencies
-include $(DEPS)

# Install packaged program
.PHONY: install
install: all copyassets
	@echo "Packaging program to $(INSTALL_DIR)"
	@mkdir -p $(INSTALL_DIR) && cp -r $(BIN_DIR)/. $(INSTALL_DIR)

# Build and run
.PHONY: run
run: all
	@echo "Starting program: $(BIN_DIR)/$(EXEC)"
    ifeq ($(OS),macos) # Open app bundle if on macOS
		@open $(BIN_DIR)/$(EXEC)
    else
		@cd $(BIN_DIR) && ./$(EXEC)
    endif

# Copy assets to bin directory for selected platform
.PHONY: copyassets
copyassets:
	@echo "Copying assets from $(ASSETS_DIR) and $(ASSETS_OS_DIR) to $(BIN_DIR)"
	@mkdir -p $(BIN_DIR)
	@cp -r $$(find $(ASSETS_DIR) -mindepth 1 -maxdepth 1 ! -path '*/metadata') $(BIN_DIR)/
	@cp -r -L $(ASSETS_OS_DIR)/. $(BIN_DIR)/ 2> /dev/null || :

# Clean all assets from bin directories for all platforms
.PHONY: cleanassets
cleanassets:
	@echo "Cleaning assets for all platforms"
	@find $(BIN_DIR_ROOT) -mindepth 3 ! -name $(EXEC) -delete

# Clean build and bin directories for all platforms
.PHONY: clean
clean:
	@echo "Cleaning $(BUILD_DIR_ROOT) and $(BIN_DIR_ROOT) directories"
	@$(RM) -r $(BUILD_DIR_ROOT)
	@$(RM) -r $(BIN_DIR_ROOT)

.PHONY: compdb
compdb: $(BUILD_DIR_ROOT)/compile_commands.json

# Generate JSON compilation database (compile_commands.json) by merging fragments
$(BUILD_DIR_ROOT)/compile_commands.json: $(COMPDBS)
	@echo "Generating: $@"
	@mkdir -p $(@D)
	@printf "[\n" > $@
	@sed -e '$$s/$$/,/' -s $(COMPDBS) | sed -e '$$s/,$$//' -e 's/^/    /' >> $@
	@printf "]\n" >> $@

# Generate JSON compilation database fragments from source files
$(BUILD_DIR)/%.json: $(SRC_DIR)/%.cpp
	@mkdir -p $(@D)
	@printf "\
	{\n\
	    \"directory\": \"$(CURDIR)\",\n\
	    \"command\": \"$(CXX) $(CPPFLAGS) $(CXXFLAGS) $(WARNINGS) -c $< -o $(basename $@).o\",\n\
	    \"file\": \"$<\"\n\
	}\n" > $@

# Run clang-format on source code
.PHONY: format
format:
	@echo "Running clang-format"
	@clang-format -i $(FILES)

# Dry-run clang-format on source code to check for formatting errors
.PHONY: format-check
format-check:
	@echo "Checking clang-format"
	@clang-format --dry-run --Werror $(FILES)

# Run clang-tidy on source code
.PHONY: lint
lint: compdb
	@echo "Running clang-tidy"
	@clang-tidy -p $(BUILD_DIR_ROOT) --warnings-as-errors='*' $(FILES)

# Run clang-tidy on source code and fix found errors
.PHONY: lint-fix
lint-fix: compdb
	@echo "Running clang-tidy --fix"
	@clang-tidy -p $(BUILD_DIR_ROOT) --fix $(FILES)

# Generate documentation with Doxygen
.PHONY: docs
docs:
	@echo "Generating documentation"
	@doxygen docs/Doxyfile

# Print help information
.PHONY: help
help:
	@printf "\
	Usage: make target... [options]...\n\
	\n\
	Targets:\n\
	  all             Build executable (debug mode by default) (default target)\n\
	  install         Install packaged program to desktop (debug mode by default)\n\
	  run             Build and run executable (debug mode by default)\n\
	  copyassets      Copy assets to executable directory for selected platform and configuration\n\
	  cleanassets     Clean assets from executable directories (all platforms)\n\
	  clean           Clean build and bin directories (all platforms)\n\
	  compdb          Generate JSON compilation database (compile_commands.json)\n\
	  format          Format source code using clang-format\n\
	  format-check    Check that source code is formatted using clang-format\n\
	  lint            Lint source code using clang-tidy\n\
	  lint-fix        Lint and fix source code using clang-tidy\n\
	  docs            Generate documentation with Doxygen\n\
	  help            Print this information\n\
	  printvars       Print Makefile variables for debugging\n\
	\n\
	Options:\n\
	  release=1       Run target using release configuration rather than debug\n\
	  win32=1         Build for 32-bit Windows (valid when built on Windows only)\n\
	  ios=1           Build for iOS (valid when built on macOS only)\n\
	\n\
	Note: the above options affect the all, install, run, copyassets, compdb, and printvars targets\n"

# Print Makefile variables
.PHONY: printvars
printvars:
	@printf "\
	OS: \"$(OS)\"\n\
	EXEC: \"$(EXEC)\"\n\
	BUILD_DIR: \"$(BUILD_DIR)\"\n\
	BIN_DIR: \"$(BIN_DIR)\"\n\
	ASSETS_DIR: \"$(ASSETS_DIR)\"\n\
	ASSETS_OS_DIR: \"$(ASSETS_OS_DIR)\"\n\
	INSTALL_DIR: \"$(INSTALL_DIR)\"\n\
	SRC_DIR: \"$(SRC_DIR)\"\n\
	SRCS: \"$(SRCS)\"\n\
	INCLUDE_DIR: \"$(INCLUDE_DIR)\"\n\
	INCLUDES: \"$(INCLUDES)\"\n\
	CXX: \"$(CXX)\"\n\
	CPPFLAGS: \"$(CPPFLAGS)\"\n\
	CXXFLAGS: \"$(CXXFLAGS)\"\n\
	WARNINGS: \"$(WARNINGS)\"\n\
	LDFLAGS: \"$(LDFLAGS)\"\n\
	LDLIBS: \"$(LDLIBS)\"\n"

# Made by Misha Krieger-Raynauld (https://github.com/KRMisha/Makefile)