Makefile.common

###########################################################################
# Standard Make variable definitions
#
# These are the common variable definitions used across different projects.
# This will usually be included at the top of a separate project specific
# Makefile using 'include Makefile.common'.
###########################################################################
#==========================================================================
# Command-line options
# Modify for your system -or- use command-line argument OPTION=string
#==========================================================================
#--------------------------------------------------------------------------
# Operating system variables
#--------------------------------------------------------------------------
# Operating system: 'macosx', 'linux', or 'windows'

ifndef PLATFORM
	UNAME := $(shell uname)
	ifeq ($(UNAME), Linux)
		PLATFORM = linux

	else ifeq ($(UNAME), Darwin)
		PLATFORM = macosx
		ifneq ($(shell sw_vers -productName),macOS)
			OSX_VERSION := $(shell sw_vers -productVersion)
			OSX_VERSION := $(word 2,$(subst ., , $(OSX_VERSION)))
		endif

	else
		PLATFORM = windows

		# uname returns:
		# MSYS/MinGW:		MINGW32_NT-6.2
		# MSYS2/MinGW-32:	MINGW32_NT-10.0
		# MSYS2/MinGW-64:	MINGW64_NT-10.0
		# MSYS2:			MSYS_NT-10.0
		ifneq (,$(findstring MINGW32,$(UNAME)))
			MINGW_VERSION := 32
		else ifneq (,$(findstring MINGW64,$(UNAME)))
			MINGW_VERSION := 64
		else ifneq (,$(findstring MSYS_NT,$(UNAME)))
			MINGW_VERSION := 64
		endif

		# uname -o returns 'Msys' for both Msys and Msys2, so can't be used
		ifneq (,$(wildcard /msys.bat))
			MSYS_VERSION := 1
		else
			MSYS_VERSION := 2
		endif
	endif
endif


# Architecture: '32' or '64'
UNAMEM := $(shell uname -m)
ifeq ($(shell which getconf 2>/dev/null),)
	ifeq ($(UNAMEM), $(findstring $(UNAMEM), x86_64 ia86 amd64 arm64))
		ARCH = 64
	else
		ARCH = 32
	endif
else
	# Set equal to number of bits in a type long int
	ARCH := $(shell getconf LONG_BIT)
endif


#--------------------------------------------------------------------------
# Build settings
#--------------------------------------------------------------------------
# Language version
CXX_VERSION ?= 14
ifneq ($(CXX_VERSION),)
	CXXFLAGS += -std=c++$(CXX_VERSION)
endif

# Name of the library
# This should be defined prior to including this file
LIB_NAME ?=

# Dynamic library major/minor version numbers
DLIB_MAJ = 1
DLIB_MIN = 0

# Build configuration: 'Release' or 'Debug'
# 'Release' aggressively optimizes for speed at the expense of greater
# compile times and program size. 'Debug' generates code suitable for a
# debugging tool.
BUILD_CONFIG = Release

# Whether to build a dynamic library versus a static library
DYNAMIC = 0

# Whether to show verbose output
VERBOSE	= 0

# Whether Make should determine the dependencies of each C or C++ file as
# it compiles it. This will be automatically disabled for universal builds
# on Mac OSX.
DEP_TRACK = 1

# Whether to enable strict warnings
STRICT_WARNINGS = 0

# Whether to automatically run executables after building
AUTORUN = 1

# Platform-specific library file extensions
SLIB_EXT = a
DLIB_EXT = so
DLIB_OPT = shared

# Flags required for including and linking against library
LINK_CPPFLAGS ?=
LINK_LDFLAGS ?=

# Flags handed to 'ar' command
SLIB_FLAGS ?=
DLIB_FLAGS ?=

#--------------------------------------------------------------------------
# Default paths
#--------------------------------------------------------------------------
PREFIX		= /usr/local/
CONFPREFIX	= $(PREFIX)/etc/
MANPREFIX	= $(PREFIX)/share/man/

# Locations of built objects
BUILD_DIR	?= build/
BIN_DIR		= $(BUILD_DIR)bin/
OBJ_DIR		= $(BUILD_DIR)obj/

# Location of library installation
DESTDIR		= $(PREFIX)

# Check for some common shared library directories
ifneq ($(wildcard /usr/local/),)
	HAS_USR_LOCAL = 1
endif
ifneq ($(wildcard /opt/local/),)
	HAS_OPT_LOCAL = 1
endif
ifneq ($(wildcard /usr/X11/),)
	HAS_USR_X11 = 1
endif

# Platform-dependent directory
PLATFORM_DIR ?=

#--------------------------------------------------------------------------
# Default tools/commands
#--------------------------------------------------------------------------

# NOTE: ar -s is completely equivalent to running ranlib
AR = ar crs
INSTALL = install
RANLIB = ranlib
RM = rm -f
DBG = gdb

# Let user override variables
-include Makefile.user

#--------------------------------------------------------------------------
# Finalize variables
#--------------------------------------------------------------------------

# Dependency tracking doesn't work with universal libraries, so disable it
ifeq ($(ARCH), 32_64)
	DEP_TRACK = 0
endif

# Emscripten (is Unix-like)
ifeq ($(PLATFORM), em)
	AR = emar crs
	RANLIB = emranlib

	LDFLAGS	 += -lm
	LDFLAGS	 += -lstdc++

	DLIB_FLAGS += -shared
	DLIB_FLAGS += -Wl,-soname,$(DLIB_MAJ_FILE)

# Linux:
else ifeq ($(PLATFORM), linux)

	PLATFORM_DIR = linux/

	ifeq ($(ARCH), 32)
		CFLAGS += -m32
	else ifeq ($(ARCH), 64)
		CFLAGS += -m64
	else ifeq ($(ARCH), 32_64)
		CFLAGS += -m32 -m64
	endif

	CPPFLAGS += -D__LINUX__ -DLINUX
	CPPFLAGS += -I/usr/local/include/ -I/usr/include/
	LDFLAGS	 += -lm
	LDFLAGS	 += -lstdc++

	DLIB_FLAGS += -shared
	DLIB_FLAGS += -Wl,-soname,$(DLIB_MAJ_FILE)

# Mac OSX:
else ifeq ($(PLATFORM), macosx)

	PLATFORM_DIR = osx/

	# BUILD_ARCHS is a space-separated list in double quotes
	ifdef BUILD_ARCHS
		CFLAGS += $(addprefix -arch ,$(BUILD_ARCHS))
	else
		ifneq (,$(findstring $(UNAMEM),arm64 x86_64))
			CFLAGS += -arch $(UNAMEM)
		else ifeq ($((UNAMEM)), ia86)
			CFLAGS += -arch i386
		endif
	endif

	# Oh where, oh where have my SDKs gone?
	CHECK_SDK_DIR = /Applications/Xcode.app
	ifeq ($(wildcard $(CHECK_SDK_DIR)),)
		CHECK_SDK_DIR = /Library/Developer/CommandLineTools/SDKs/
		ifeq ($(wildcard $(CHECK_SDK_DIR)),)
			OSX_SDK_PATH := /Developer/SDKs/
		else
			OSX_SDK_PATH := $(CHECK_SDK_DIR)
		endif
	else
		OSX_SDK_PATH := $(CHECK_SDK_DIR)/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/
	endif

	# Set system root directory for stdc++ etc.
	OSX_SDK := $(lastword $(shell ls $(OSX_SDK_PATH)))
	CFLAGS += -isysroot $(OSX_SDK_PATH)$(OSX_SDK) 
	
	ifdef OSX_VERSION
		CFLAGS += -mmacosx-version-min=10.$(OSX_VERSION)
	endif

	# Needed to link to libraries installed through MacPorts
	ifdef HAS_OPT_LOCAL
		LDFLAGS  += -L/opt/local/lib/
		CPPFLAGS += -I/opt/local/include/
	endif

	# Needed to link to libraries installed through homebrew or by user
	ifneq ($(wildcard /usr/local/lib),)
		LDFLAGS  += -L/usr/local/lib/
	endif
	ifneq ($(wildcard /usr/local/include),)
		CPPFLAGS += -I/usr/local/include/
	endif

	LDFLAGS	+= -lm
	LDFLAGS	+= -lstdc++
	DLIB_EXT = dylib
	DLIB_OPT = dynamiclib

	DLIB_FLAGS += -dynamiclib
	DLIB_FLAGS += -current_version $(DLIB_MAJ).$(DLIB_MIN) -compatibility_version $(DLIB_MAJ).$(DLIB_MIN)

# Windows:
else ifeq ($(PLATFORM), windows)

	PLATFORM_DIR = windows/

	ifeq ($(MSYS_VERSION), 2)
		LDFLAGS  += -L/usr/lib/
		CPPFLAGS += -I/usr/include/
		CPPFLAGS += -D_WIN$(MINGW_VERSION)
		PREFIX := /mingw$(MINGW_VERSION)/
	else ifeq ($(MSYS_VERSION), 1)
		LDFLAGS  += -L/mingw/lib/
		CPPFLAGS += -I/mingw/include/
		PREFIX := /local/
		CC := gcc
		# This fixes a bug in MINGW/MSYS math.h (!!!)
		CPPFLAGS += -U _hypot -D _hypot=hypot
	endif

	# Location of user installed libs
	LDFLAGS += -L$(PREFIX)/lib/
	CPPFLAGS += -I$(PREFIX)/include/

	CPPFLAGS += -I`pwd`

#	SLIB_EXT = lib
#	DLIB_EXT = dll
endif


# Whether to echo commands to the terminal...
ifeq ($(VERBOSE), 0)
	AR  := @$(AR)
	CC  := @$(CC)
	CXX := @$(CXX)
	#Redundant, gdb echoes by default
	#DBG := @$(DBG)
endif

# Append optimization flags
ifeq ($(BUILD_CONFIG), Release)
	CPPFLAGS += -DNDEBUG
	CFLAGS += -O3
	#CFLAGS += -flto=8 # link-time optimization
	#CFLAGS += -fpeel-loops # not supported by clang
else
	CFLAGS += -O0 -fno-inline 

	ifeq ($(BUILD_CONFIG), Debugger)
		CFLAGS += -ggdb3
	endif
endif

# Append warning flags
ifneq ($(STRICT_WARNINGS), 0)
	# See https://gcc.gnu.org/onlinedocs/gcc/Warning-Options.html
	CFLAGS += \
		-Wreturn-type \
		-Wformat -Wmissing-braces -Wparentheses -Wswitch \
		-Wunused-variable -Wsign-compare -Wno-unknown-pragmas \
		-Wuninitialized -Winit-self
	CXXFLAGS += -Wnon-virtual-dtor -Woverloaded-virtual
endif

# Turn some warnings into errors as they can cause program crashes
CFLAGS += -Werror=return-type

SLIB_FILE	= lib$(LIB_NAME).$(SLIB_EXT)
DLIB_FILE	= lib$(LIB_NAME).$(DLIB_EXT)
DLIB_MAJ_FILE	= lib$(LIB_NAME).$(DLIB_MAJ).$(DLIB_EXT)
DLIB_MIN_FILE	= lib$(LIB_NAME).$(DLIB_MAJ).$(DLIB_MIN).$(DLIB_EXT)
DLIB_PATH	= $(addprefix $(BUILD_DIR)lib/, $(DLIB_MIN_FILE))
SLIB_PATH	= $(addprefix $(BUILD_DIR)lib/, $(SLIB_FILE))

# Set file directory/name of specified library type
ifneq ($(DYNAMIC), 0)
	CFLAGS += -fPIC
	LIB_FILE = $(DLIB_MIN_FILE)
	LIB_PATH = $(DLIB_PATH)
else
	LIB_FILE = $(SLIB_FILE)
	LIB_PATH = $(SLIB_PATH)
endif


#--------------------------------------------------------------------------
# Utility functions
#--------------------------------------------------------------------------
RemoveDir = @if test -d $(1); then $(RM) $(1)* && rmdir $(1); fi

define RemoveBuildDir
       $(call RemoveDir, $(BUILD_DIR)include/)
       $(call RemoveDir, $(BUILD_DIR)lib/)
       $(call RemoveDir, $(BIN_DIR))
       $(call RemoveDir, $(OBJ_DIR))
       $(call RemoveDir, $(BUILD_DIR))
endef