MAKEFLAGS += -R -r

prefix   := $(CURDIR)
export PATH := $(prefix)/gnu/bin:$(PATH)

tooldir   = riscv-gnu-toolchain
binutils  = $(tooldir)/riscv-binutils

# --disable-gdb because the gdb with riscv-gnu-toolchain seems really broken
all_config = --prefix=$(prefix)/gnu --with-system-zlib


z80_config = $(all_config) \
	   --target=z80-none-elf

riscv_target_flags = -fvisibility=hidden -fno-pic -mshorten-memrefs \
		     -frename-registers -mdiv -mno-strict-align \
		     -ffunction-sections -fdata-sections

riscv_config = $(all_config) \
	    --with-arch=rv32imc --with-abi=ilp32 \
	    --with-target-cflags='$(riscv_target_flags)' \
	    --with-target-cxxflags='$(riscv_target_flags)' \
	    --enable-multilib --with-multilib-generator='rv32imc-ilp32--'

# The tools don't seem to build correctly without buildin rules (sigh)
# There isn't even an option to cancel them, so use this hideousness
# to strip out the r and R option from MAKEFLAGS.
_tail = $(wordlist 2,$(words $(1)),$(1))
_strip_flags = $(if $(1),$(call _strip_flags,$(call _tail,$(1)),$(subst $(word 1,$(1)),,$(2))),$(2))
strip_flags  = $(if $(findstring -,$(word 1,$(2))),$(2),$(call _strip_flags,$(1),$(word 1,$(2))) $(call _tail,$(2)))

RMAKE = $(MAKE) MAKEFLAGS='$(call strip_flags,r R,$(MAKEFLAGS))'

riscv_configargs := target_configargs='--enable-lite-exit --disable-newlib-register-fini'

all: gnu.riscv.build gnu.z80.build

clean:
	rm -rf *.build *~ *.bak \#* .\#*

spotless: clean
	rm -rf gnu

.PHONY: src
src:
	[ ! -f ../../.gitmodules ] || \
		git submodule update --init --recursive

# Note: the riscv-gnu-toolchain repo has bugs when building in
# parallel, so spoon feed it a sequence to avoid dependency problems.
.PHONY: gnu.riscv.build
gnu.riscv.build: src
	mkdir -p $@
	cd $@ && $(riscv_configargs) ../$(tooldir)/configure $(riscv_config)
	$(RMAKE) -C $@ $(riscv_configargs) build-binutils
	$(RMAKE) -C $@ $(riscv_configargs) newlib

.PHONY: gnu.z80.build
gnu.z80.build: src
	mkdir -p $@
	cd $@ && ../$(binutils)/configure $(z80_config)
	$(RMAKE) -C $@
	$(RMAKE) -C $@ install