AR = ar
CC = gcc
CFLAGS = -Wall -g -O3 -march=native

arch = x86_64

cflags = -pipe -std=c99 -nostdinc -D_XOPEN_SOURCE=700 \
	-ffreestanding -fexcess-precision=standard -fno-strict-aliasing \
	-frounding-math -fno-pic -fno-stack-protector \
	-fno-unwind-tables -fno-asynchronous-unwind-tables \
	-ffunction-sections -fdata-sections \
	-Iarch/$(arch) -Iarch/generic -Isrc/include -Isrc/internal \
	-Igenerated/include -Iinclude $(CFLAGS)

prefix = /
includedir = $(prefix)/include
libdir = $(prefix)/lib

src_dirs = src/* src/mallocng crt
common_src = $(wildcard $(addsuffix /*.c, $(src_dirs)))
arch_src = $(wildcard $(addsuffix /$(arch)/*.[csS], $(src_dirs)))

common_obj = $(common_src:.c=.o)
arch_obj = $(patsubst %, %.o, $(basename $(arch_src)))
replaced_obj = $(subst /$(arch)/,/, $(arch_obj))
all_obj = $(filter-out $(replaced_obj), $(common_obj) $(arch_obj))
memops_obj = $(filter %/memcpy.o %/memmove.o %/memcmp.o %/memset.o, $(all_obj))
crt_obj = $(filter crt/%, $(all_obj))

generated_headers = $(addprefix generated/include/bits/, \
		    alltypes.h syscall.h)
implementation_headers = $(addprefix src/internal/, \
			 stdio_impl.h pthread_impl.h locale_impl.h libc.h)

lib_obj = libc.a crt1.o crti.o crtn.o

arch_inc = $(wildcard arch/$(arch)/bits/*.h)
generic_inc = $(wildcard arch/generic/bits/*.h)
inc = $(wildcard include/*.h include/*/*.h)
all_inc = $(sort $(inc) $(generated_headers:generated/%=%) \
	  $(arch_inc:arch/$(arch)/%=include/%) \
	  $(generic_inc:arch/generic/%=include/%))

default: $(lib_obj)

generated_dirs:
	mkdir -p $(dir $(generated_headers))

$(generated_headers): | generated_dirs

generated/include/bits/alltypes.h: arch/$(arch)/bits/alltypes.h.in \
	include/alltypes.h.in
	sed -f tools/mkalltypes.sed $^ >$@

generated/include/bits/syscall.h: arch/$(arch)/bits/syscall.h.in
	cp $< $@
	sed -n  -e 's/__NR_/SYS_/p' < $< >>$@

src/internal/version.o: cflags += -DVERSION=\"$(shell cat VERSION)\"
crt/crt1.o: arch/$(arch)/crt_arch.h
$(memops_obj): cflags += -fno-tree-loop-distribute-patterns
$(crt_obj): cflags += -DCRT

cc_cmd = $(CC) $(cflags) -c -o $@ $<
as_cmd = $(cc_cmd)
install_cmd = install -D -m 644 $< $@

%.o: %.s
	$(as_cmd)

%.o: %.S
	$(cc_cmd)

%.o: %.c $(generated_headers) $(implementation_headers)
	$(cc_cmd)

%.o: crt/$(arch)/%.o
	cp $< $@
%.o: crt/%.o
	cp $< $@

libc.a: $(all_obj)
	rm -f $@
	$(AR) rcs $@ $^

$(DESTDIR)$(libdir)/%: %
	$(install_cmd)

$(DESTDIR)$(includedir)/bits/%: arch/$(arch)/bits/%
	$(install_cmd)

$(DESTDIR)$(includedir)/bits/%: arch/generic/bits/%
	$(install_cmd)

$(DESTDIR)$(includedir)/bits/%: generated/include/bits/%
	$(install_cmd)

$(DESTDIR)$(includedir)/%: include/%
	$(install_cmd)

install-libs: $(addprefix $(DESTDIR)$(libdir)/, $(lib_obj))
install-headers: $(all_inc:include/%=$(DESTDIR)$(includedir)/%)
install: install-libs install-headers

clean:
	rm -rf generated
	rm -f crt/*.o src/*/*.o libc.a crt1.o crti.o crtn.o