CC := avr-gcc
AR := avr-ar
SIZE := avr-size
OBJDUMP = avr-objdump

SRCDIR := src
BUILDDIR := build
INCDIR := include
LIBDIR := lib
LIB := libcommon

SRCEXT := c
SOURCES := $(shell find $(SRCDIR) -type f -name *.$(SRCEXT))
OBJECTS := $(patsubst $(SRCDIR)/%,$(BUILDDIR)/%,$(SOURCES:.$(SRCEXT)=.o))

INC := -I $(INCDIR)

# AR flags
ARFLAGS := rcs

MCU = atmega328p

## Language standard
CFLAGS += -std=gnu99

## Definitions
CFLAGS += -DF_CPU=16000000L -D__AVR__ -D__AVR_ATmega328P__

## Tuning
CFLAGS += -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums

# Debugging format.
# Native formats for AVR-GCC's -g are stabs [default], or dwarf-2.
# AVR (extended) COFF requires stabs, plus an avr-objcopy run.
DEBUG_FORMAT = stabs

ifeq ($(BUILD),debug)
	CFLAGS += -DDEBUG -g$(DEBUG_FORMAT)
	CFLAGS += -Wall -Wextra -Wformat=2 -Wswitch-default \
			  -Wcast-align -Wpointer-arith -Wbad-function-cast \
			  -Wstrict-prototypes -Winline -Wundef -Wnested-externs \
			  -Wcast-qual -Wshadow -Wwrite-strings -Wconversion \
			  -Winit-self -Wstrict-aliasing -Wmissing-declarations \
			  -Wmissing-include-dirs -Wno-unused-parameter -Wuninitialized \
			  -Wold-style-definition -Wmissing-prototypes -Wunreachable-code \
			  -Wno-unused-but-set-variable -Wmaybe-uninitialized
	CINCS += -I /usr/include/simavr
	#
else
	CFLAGS += -DNDEBUG -s -Os
endif

.PHONY: clean debug all

all: lib

lib: $(LIBDIR)/$(LIB).a

debug_header:
	@echo "================================================="
	@echo "Debug build initiated..."
	@echo "--------"

debug: clean debug_header
	$(MAKE) "BUILD=debug"

$(BUILDDIR)/%.o: $(SRCDIR)/%.$(SRCEXT)
	@echo "================================================="
	@echo "Building objects..."
	@echo "--------"
	@mkdir -p $(BUILDDIR)
	@mkdir -p $(LIBDIR)
	@mkdir -p $(INCDIR)
	$(CC) $(CFLAGS) $(INC) -c -o $@ $<

.SECONDARY: $(OBJ)
%.a: $(OBJECTS)
	@echo "================================================="
	@echo "Building static library..."
	@echo "--------"
	$(AR) $(ARFLAGS) $(LIBDIR)/$(LIB).a $(OBJECTS)

clean:
	@echo "================================================="
	@echo "Cleaning up build files...";
	@rm -rf $(BUILDDIR) $(LIBDIR)