My makefile

CC=gcc
SOURCES=main.c func.c
AUTOTEST=AutoTest.c
OBJECTS=$(SOURCES:.c=.o)
OUTPUT=program

all: $(OBJECTS)
	$(CC) $(OBJECTS) -o $(OUTPUT)

$(SOURCES):
	$(CC) -c $@ -o $(@:.o=.c)

autotest: $(OBJECTS) $(AUTOTEST:.c=.o)
	$(CC) -D AUTOTEST -c main.c
	$(CC) $(OBJECTS) $(AUTOTEST:.c=.o) -o $(OUTPUT)

$(AUTOTEST):
	$(CC) -c $@

clean:
	rm -rf $(OBJECTS) $(AUTOTEST:.c=.o) $(OUTPUT)