ifneq (,$(wildcard ./.env))
  include .env
  export
else
  $(warning .env file not found, loading defaults)
  include .env.example
  export
endif

RISCV_CC ?= riscv64-unknown-elf-gcc
RISCV_ARCH_FLAGS ?= -march=rv32im -mabi=ilp32
HOST_CC ?= gcc
HOST_CFLAGS ?= -Wall -Wextra -O3 -g
HOST_LDFLAGS ?= -Wl,-s

EMU_SRC_FILES := $(wildcard src/emulated/*.c)
EMU_OBJ_FILES := $(EMU_SRC_FILES:src/emulated/%.c=build/%.riscv.o)
EMU_OBJ := build/emulated.riscv.elf

GENERATED := build/include/generated.h

HOST_SRC := src/main.c src/elf.c

ifeq ($(OS),Windows_NT)
    HOST_EXE := build/main.exe
else
    HOST_EXE := build/main
endif

# Disassembly
RISCV_OBJDUMP ?= $(patsubst %-gcc,%-objdump,$(RISCV_CC))
_DISAS_TARGETS := $(filter disas-%,$(MAKECMDGOALS))
_DISAS_FILES   := $(if $(_DISAS_TARGETS),$(filter %.elf %.o,$(MAKECMDGOALS)))



.PHONY: all emulated-riscv host clean disas-risc

all: $(HOST_EXE) $(EMU_OBJ)

emulated-riscv: $(EMU_OBJ)

host: $(HOST_EXE)

$(HOST_EXE): $(HOST_SRC) tinyriscv/src/tinyriscv.h src/config.h src/elf.h | build
	$(HOST_CC) $(HOST_CFLAGS) $(HOST_LDFLAGS) -I src -I tinyriscv/src $(HOST_SRC) -o $@

build/%.riscv.o: src/emulated/%.c $(GENERATED) | build
	$(RISCV_CC) $(RISCV_ARCH_FLAGS) -I $(dir $(GENERATED)) -I src/emulated -c $< -o $@

$(EMU_OBJ): $(EMU_OBJ_FILES) | build
	$(RISCV_CC) $(RISCV_ARCH_FLAGS) -nostdlib -Wl,-e,entry -Wl,-Ttext=0 $(EMU_OBJ_FILES) -o $@


.FORCE:

$(GENERATED): .FORCE
	mkdir -p $(dir $@)
	python codegen/generate.py $(FLAG_PREFIX) $(FLAG_LEN) > $@


build:
	mkdir -p $@

clean:
	rm -rf build

disas-risc: $(_DISAS_FILES)
	$(RISCV_OBJDUMP) -d $^