LIBC_DIR := $(LUNA_ROOT)/libs/libc
LIBC_SRC := $(LIBC_DIR)/src
LIBC_OBJ := $(LIBC_DIR)/lib
LIBC_BIN := $(LIBC_DIR)/bin

DESTDIR ?= $(LUNA_BASE)/usr/lib

CFLAGS := -Os -nostdlib -ffunction-sections -fdata-sections -fno-asynchronous-unwind-tables -fno-omit-frame-pointer -pedantic -Wall -Wextra -Werror -Wfloat-equal -Wdisabled-optimization -Wformat=2 -Winit-self -Wmissing-include-dirs -Wswitch-default -Wcast-qual -Wundef -Wcast-align -Wwrite-strings -Wlogical-op -Wredundant-decls -Wshadow -Wconversion
CXXFLAGS := -fno-rtti -fno-exceptions -Wsign-promo -Wstrict-null-sentinel -Wctor-dtor-privacy
ASMFLAGS := -felf64

rwildcard=$(foreach d,$(wildcard $(1:=/*)),$(call rwildcard,$d,$2) $(filter $(subst *,%,$2),$d))

CXX_SRC = $(call rwildcard,$(LIBC_SRC),*.cpp)
C_SRC = $(call rwildcard,$(LIBC_SRC),*.c)
ASM_SRC = $(call rwildcard,$(LIBC_SRC),*.asm)

OBJS = $(patsubst $(LIBC_SRC)/%.cpp, $(LIBC_OBJ)/%.cpp.o, $(CXX_SRC))
OBJS += $(patsubst $(LIBC_SRC)/%.c, $(LIBC_OBJ)/%.c.o, $(C_SRC))
OBJS += $(patsubst $(LIBC_SRC)/%.asm, $(LIBC_OBJ)/%.asm.o, $(ASM_SRC))

$(LIBC_OBJ)/%.cpp.o: $(LIBC_SRC)/%.cpp
	@mkdir -p $(@D)
	@$(CXX) $(CFLAGS) $(CXXFLAGS) -o $@ -c $^
	@echo "  CXX $^"

$(LIBC_OBJ)/%.c.o: $(LIBC_SRC)/%.c
	@mkdir -p $(@D)
	@$(CC) $(CFLAGS) -o $@ -c $^
	@echo "  CC $^"

$(LIBC_OBJ)/%.asm.o: $(LIBC_SRC)/%.asm
	@mkdir -p $(@D)
	@$(ASM) $(ASMFLAGS) -o $@ $^
	@echo "  ASM $^"

$(LIBC_BIN)/libc.a: $(OBJS)
	@mkdir -p $(@D)
	@$(AR) rcs $@ $(OBJS)
	@echo "  AR $@"

$(LIBC_BIN)/crt0.o: $(LIBC_DIR)/crt0.asm
	@mkdir -p $(@D)
	@$(ASM) $(ASMFLAGS) -o $@ $^
	@echo "  ASM $^"

$(LIBC_BIN)/crti.o: $(LIBC_DIR)/crti.asm
	@mkdir -p $(@D)
	@$(ASM) $(ASMFLAGS) -o $@ $^
	@echo "  ASM $^"

$(LIBC_BIN)/crtn.o: $(LIBC_DIR)/crtn.asm
	@mkdir -p $(@D)
	@$(ASM) $(ASMFLAGS) -o $@ $^
	@echo "  ASM $^"

build: $(LIBC_BIN)/crt0.o $(LIBC_BIN)/crti.o $(LIBC_BIN)/crtn.o $(LIBC_BIN)/libc.a

$(DESTDIR)/libc.a: $(LIBC_BIN)/libc.a
	@mkdir -p $(@D)
	@cp $^ $@
	@rm -f $(DESTDIR)/libm.a
	@ln -s $@ $(DESTDIR)/libm.a
	@echo "  INSTALL $^"

$(DESTDIR)/crt0.o: $(LIBC_BIN)/crt0.o
	@mkdir -p $(@D)
	@cp $^ $@
	@echo "  INSTALL $^"

$(DESTDIR)/crti.o: $(LIBC_BIN)/crti.o
	@mkdir -p $(@D)
	@cp $^ $@
	@echo "  INSTALL $^"

$(DESTDIR)/crtn.o: $(LIBC_BIN)/crtn.o
	@mkdir -p $(@D)
	@cp $^ $@
	@echo "  INSTALL $^"

install: $(DESTDIR)/libc.a $(DESTDIR)/crt0.o $(DESTDIR)/crti.o $(DESTDIR)/crtn.o

clean:
	rm -rf $(LIBC_OBJ)/*
	rm -rf $(LIBC_BIN)/*
	rm -f $(DESTDIR)/libc.a
	rm -f $(DESTDIR)/crt*.o