Makefile.libretro

###########################################################################
#
#   Makefile.libretro
#
#   Makefile for building MAME and derivatives as libretro core libraries
#
#   Copyright (C) 2015 Libretro Team.
#   Licensing should be regarded as the same as that of the MAME project,
#   visit http://mamedev.org for more information.
#
#
#   Okay, basically this file exists to do the following:
#
#   1. Determine $ARCH and $platform from the cmdline, the environment, or
#      by figuring them out (as other libretro cores do).
#   2. Disable -Werror.  MAME upstream builds with -Werror, which is great
#      for developers but absolutely frustrating for users.  From our POV,
#      we're effectively users, and users who try to follow the bleeding
#      edge no less.  That means we get cut, and too often it's by some
#      random warning upstream hasn't squashed.
#   3. Set PYTHON_EXECUTABLE on non-Apple platforms.  Upstream assumes
#      python (no prefix) is python2, which basically NEVER happens now on
#      modern Linux systems, and isn't even common on Windows anymore.  It
#      should be python2 pretty much everywhere but Apple, and the exception
#      there is mostly because Apple hates GPLv3.
#   4. Enable VERBOSE.  Yes, MAME builds generate a metric crap-ton of
#      output, but when builds fail it's nice to know why.
#   5. Rename $ARCH and unset it.  Apple has a convention on the Mac of
#      letting you use $ARCH to specify what CPU architectures to build
#      for.  This is at odds to how libretro uses it, and solving that on
#      the libretro end is going to have to wait for a major overhaul of
#      how cores are built.  We're not ready to do that yet.
#
###########################################################################

###########################################################################
#
#   LIBRETRO PREFERRED DEFAULT SETTINGS
#
###########################################################################

# Disable -Werror as libretro is effectively a MAME user, not a developer
NOWERROR ?= 1

# This needs to be python2 at the moment everywhere but OS X (fixed later)
PYTHON_EXECUTABLE ?= python2

# Cause the build system to regenerate itself, in case it changed
REGENIE ?= 1

# Spew much output developers need if MAME's build breaks for some reason
VERBOSE ?= 1

# You probably shouldn't need to set this anymore (find libretro section of
# scripts/toolchain.lua)
# PTR64 = 1

USE_BGFX ?= 0

###########################################################################
#
#   LIBRETRO PLATFORM GUESSING
#
#   If the caller doesn't specify $platform and $ARCH, we guess
#
###########################################################################

UNAME_S = $(shell uname -s)
UNAME_M = $(shell uname -m)
ifeq ($(platform),)
	platform = unix
	ifeq ($(UNAME_S),)
		platform = win
	else ifneq ($(findstring MINGW,$(UNAME_S)),)
		platform = win
	else ifneq ($(findstring Darwin,$(UNAME_S)),)
		platform = osx
	else ifneq ($(findstring win,$(UNAME_S)),)
		platform = win
	endif
endif
ifeq ($(ARCH),)
	LIBRETRO_CPU = $(ARCH)
endif
ifeq ($(LIBRETRO_CPU),)
	ifeq ($(UNAME_M),)
		ifeq ($(PROCESSOR_ARCHITECTURE),AMD64)
			LIBRETRO_CPU = x86_64
		endif
		ifeq ($(PROCESSOR_ARCHITEW6432),AMD64)
			LIBRETRO_CPU = x86_64
		endif
	else ifeq ($(UNAME_M),amd64)
		LIBRETRO_CPU = x86_64
	else
		LIBRETRO_CPU = $(UNAME_M)
	endif
endif

###########################################################################
#
#   LIBRETRO PLATFORM-SPECIFIC CONFIGURATION
#
#   Settings needed to get MAME to build everywhere we build it
#
###########################################################################

ifeq ($(platform), android)
#	PTR64 = 0
	# FIXME: Pass these to GENie and test...
#	CROSS_BUILD = 1
#	FORCE_DRC_C_BACKEND = 1
else ifeq ($(platform), osx)
	PYTHON_EXECUTABLE = python
else ifneq (,$(findstring ios,$(platform)))
#	PTR64 = 0
        LIBRETRO_CPU=arm
	PYTHON_EXECUTABLE = python
	# FIXME: Pass these to GENie and test...
#	CROSS_BUILD = 1
#	FORCE_DRC_C_BACKEND = 1
endif


###########################################################################
#
#   BUILD FLAGS
#
###########################################################################

BUILDFLAGS = REGENIE=$(REGENIE) VERBOSE=$(VERBOSE) NOWERROR=$(NOWERROR) OSD="retro"
ifneq ($(PYTHON_EXECUTABLE),)
	BUILDFLAGS += PYTHON_EXECUTABLE=$(PYTHON_EXECUTABLE)
endif
ifeq ($(DEBUG),1)
	BUILDFLAGS += CONFIG=libretrodbg
else
	BUILDFLAGS += CONFIG=libretro
endif


###########################################################################
#
#   PLATFORM FLAGS
#
###########################################################################

PLATFLAGS =
ifneq ($(PTR64),)
	PLATFLAGS += PTR64=$(PTR64)
endif
ifneq ($(platform),)
	PLATFLAGS += LIBRETRO_OS="$(platform)"
endif
ifeq ($(platform),win)
	ifeq ($(MSYSTEM),MINGW64)
		MINGW64 ?= /mingw64
		PLATFLAGS += MINGW64="$(MINGW64)"
	else ifeq ($(MSYSTEM),MINGW32)
		MINGW32 ?= /mingw32
		PLATFLAGS += MINGW32="$(MINGW32)"
	endif
endif
ifneq ($(LIBRETRO_CPU),)
	PLATFLAGS += ARCH="" LIBRETRO_CPU="$(LIBRETRO_CPU)"
endif
ifneq ($(FORCE_DRC_C_BACKEND),)
	PLATFLAGS += FORCE_DRC_C_BACKEND="$(FORCE_DRC_C_BACKEND)"
endif

###########################################################################
#
#   TARGET FLAGS
#
###########################################################################

TARGETFLAGS =
ifneq ($(TARGET),)
	TARGETFLAGS += TARGET=$(TARGET)
endif
ifneq ($(SUBTARGET),)
	TARGETFLAGS += SUBTARGET=$(SUBTARGET)
endif


###########################################################################
#
#   MAKE RULES
#
#   We just call upstream GENie here with appropriate args
#
###########################################################################

all: build

build:
	$(MAKE) $(BUILDFLAGS) $(PLATFLAGS) $(TARGETFLAGS)

clean:
	$(MAKE) $(BUILDFLAGS) $(PLATFLAGS) $(TARGETFLAGS) clean

.PHONY: all build clean