Setup the Makefile to allow me to produce a release build and to create some directories if they're not there already.

Makefile

@@ -1,21 +1,32 @@
 CC = gcc
-CFLAGS=-Wall
+CFLAGS=-Wall -DDEBUG
 SRC=src
 OBJ=obj
 SRCS=$(wildcard $(SRC)/*.c)
+# Substitute all .c with .o from SRCS
 OBJS=$(patsubst $(SRC)/%.c, $(OBJ)/%.o, $(SRCS))
 
 BINDIR=bin
 BIN=$(BINDIR)/clox
 
-all:$(BIN)
+all: $(BIN)
 
-$(BIN): $(OBJS)
+release: CFLAGS=-Wall -O2
+release: clean
+release: $(BIN)
+
+$(BIN): $(OBJS) $(BINDIR)
 	$(CC) $(CFLAGS) $(OBJS) -o $@
 
-$(OBJ)/%.o: $(SRC)/%.c
+$(OBJ)/%.o: $(SRC)/%.c $(OBJ)
 	$(CC) $(CFLAGS) -c $< -o $@
 
+$(BINDIR):
+	mkdir $@
+
+$(OBJ):
+	mkdir $@
+
 .PHONY: clean
 .PHONY: test