OUTPUT = $(PWD)/output
SOURCES = sources

CONFIG_SUB_REV = 3d5db9ebe860
BINUTILS_VER = 2.25.1
GCC_VER = 5.3.0
MUSL_VER = 1.1.14
GMP_VER = 6.1.0
MPC_VER = 1.0.3
MPFR_VER = 3.1.4
LINUX_VER = 4.4.10

GNU_SITE = https://ftp.gnu.org/pub/gnu
GCC_SITE = $(GNU_SITE)/gcc
BINUTILS_SITE = $(GNU_SITE)/binutils
GMP_SITE = $(GNU_SITE)/gmp
MPC_SITE = $(GNU_SITE)/mpc
MPFR_SITE = $(GNU_SITE)/mpfr

MUSL_SITE = https://www.musl-libc.org/releases
MUSL_REPO = git://git.musl-libc.org/musl

LINUX_SITE = https://cdn.kernel.org/pub/linux/kernel

BUILD_DIR = build-$(TARGET)

-include config.mak

SRC_DIRS = gcc-$(GCC_VER) binutils-$(BINUTILS_VER) musl-$(MUSL_VER) \
	$(if $(GMP_VER),gmp-$(GMP_VER)) \
	$(if $(MPC_VER),mpc-$(MPC_VER)) \
	$(if $(MPFR_VER),mpfr-$(MPFR_VER)) \
	$(if $(LINUX_VER),linux-$(LINUX_VER))

all:

clean:
	rm -rf gcc-* binutils-* musl-* gmp-* mpc-* mpfr-* build-* linux-*

distclean: clean
	rm -rf sources


# Rules for downloading and verifying sources. Treat an external SOURCES path as
# immutable and do not try to download anything into it.

ifeq ($(SOURCES),sources)

$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/gmp*)): SITE = $(GMP_SITE)
$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/mpc*)): SITE = $(MPC_SITE)
$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/mpfr*)): SITE = $(MPFR_SITE)
$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/binutils*)): SITE = $(BINUTILS_SITE)
$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/gcc*)): SITE = $(GCC_SITE)/$(basename $(basename $(notdir $@)))
$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/musl*)): SITE = $(MUSL_SITE)
$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/linux-4*)): SITE = $(LINUX_SITE)/v4.x
$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/linux-3*)): SITE = $(LINUX_SITE)/v3.x
$(patsubst hashes/%.sha1,$(SOURCES)/%,$(wildcard hashes/linux-2.6*)): SITE = $(LINUX_SITE)/v2.6

$(SOURCES):
	mkdir -p $@

$(SOURCES)/config.sub: | $(SOURCES)
	mkdir -p $@.tmp
	cd $@.tmp && wget -c -O $(notdir $@) "http://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=$(CONFIG_SUB_REV)"
	cd $@.tmp && touch $(notdir $@)
	cd $@.tmp && sha1sum -c $(PWD)/hashes/$(notdir $@).$(CONFIG_SUB_REV).sha1
	mv $@.tmp/$(notdir $@) $@
	rm -rf $@.tmp

$(SOURCES)/%: hashes/%.sha1 | $(SOURCES)
	mkdir -p $@.tmp
	cd $@.tmp && wget -c -O $(notdir $@) $(SITE)/$(notdir $@)
	cd $@.tmp && touch $(notdir $@)
	cd $@.tmp && sha1sum -c $(PWD)/hashes/$(notdir $@).sha1
	mv $@.tmp/$(notdir $@) $@
	rm -rf $@.tmp

endif


# Rules for extracting and patching sources, or checking them out from git.

musl-git-%:
	rm -rf $@.tmp
	git clone -b $(patsubst musl-git-%,%,$@) $(MUSL_REPO) $@.tmp
	cd $@.tmp && git fsck
	mv $@.tmp $@

%: $(SOURCES)/%.tar.gz | $(SOURCES)/config.sub
	rm -rf $@.tmp
	mkdir $@.tmp
	( cd $@.tmp && tar zxvf - ) < $<
	test ! -d patches/$@ || cat patches/$@/* | ( cd $@.tmp/$@ && patch -p1 )
	test ! -f $@.tmp/$@/config.sub || cp -f $(SOURCES)/config.sub $@.tmp/$@
	rm -rf $@
	touch $@.tmp/$@
	mv $@.tmp/$@ $@
	rm -rf $@.tmp

%: $(SOURCES)/%.tar.bz2 | $(SOURCES)/config.sub
	rm -rf $@.tmp
	mkdir $@.tmp
	( cd $@.tmp && tar jxvf - ) < $<
	test ! -d patches/$@ || cat patches/$@/* | ( cd $@.tmp/$@ && patch -p1 )
	test ! -f $@.tmp/$@/config.sub || cp -f $(SOURCES)/config.sub $@.tmp/$@
	rm -rf $@
	touch $@.tmp/$@
	mv $@.tmp/$@ $@
	rm -rf $@.tmp

%: $(SOURCES)/%.tar.xz | $(SOURCES)/config.sub
	rm -rf $@.tmp
	mkdir $@.tmp
	( cd $@.tmp && tar Jxvf - ) < $<
	test ! -d patches/$@ || cat patches/$@/* | ( cd $@.tmp/$@ && patch -p1 )
	test ! -f $@.tmp/$@/config.sub || cp -f $(SOURCES)/config.sub $@.tmp/$@
	rm -rf $@
	touch $@.tmp/$@
	mv $@.tmp/$@ $@
	rm -rf $@.tmp


# Rules for building.

ifeq ($(TARGET),)

all:
	@echo TARGET must be set via config.mak or command line.
	@exit 1

else

$(BUILD_DIR):
	mkdir -p $@

$(BUILD_DIR)/Makefile: | $(BUILD_DIR)
	ln -sf ../litecross/Makefile $@

$(BUILD_DIR)/config.mak: | $(BUILD_DIR)
	printf >$@ -- '%s\n' \
	"MUSL_SRCDIR = ../musl-$(MUSL_VER)" \
	"GCC_SRCDIR = ../gcc-$(GCC_VER)" \
	"BINUTILS_SRCDIR = ../binutils-$(BINUTILS_VER)" \
	$(if $(GMP_VER),"GMP_SRCDIR = ../gmp-$(GMP_VER)") \
	$(if $(MPC_VER),"MPC_SRCDIR = ../mpc-$(MPC_VER)") \
	$(if $(MPFR_VER),"MPFR_SRCDIR = ../mpfr-$(MPFR_VER)") \
	$(if $(LINUX_VER),"LINUX_SRCDIR = ../linux-$(LINUX_VER)") \
	"-include ../config.mak"

all: | $(SRC_DIRS) $(BUILD_DIR) $(BUILD_DIR)/Makefile $(BUILD_DIR)/config.mak
	cd $(BUILD_DIR) && $(MAKE) $@

install: | $(SRC_DIRS) $(BUILD_DIR) $(BUILD_DIR)/Makefile $(BUILD_DIR)/config.mak
	cd $(BUILD_DIR) && $(MAKE) OUTPUT=$(OUTPUT) $@

endif