Updated the project structure, and modified the Makefile to hopefully be future proof so I can freely make sub-folders in the src/ folder and not have to worry about breaking the Makefile.

Makefile

@@ -1,17 +1,26 @@
 CC = gcc
-SOURCEFILES := $(wildcard *.c)
+CFLAGS=-Wall
+SRC=src
+OBJ=obj
+SRCS=$(wildcard $(SRC)/*.c)
+OBJS=$(patsubst $(SRC)/%.c, $(OBJ)/%.o, $(SRCS))
 
-SOURCE := $(wildcard *.c)
+BINDIR=bin
+BIN=$(BINDIR)/clox
 
-$(SOURCE:.c=.o): $(SOURCE)
-	@mkdir -p obj
-	$(CC) $^ -o obj/clox
+all:$(BIN)
+
+$(BIN): $(OBJS)
+	$(CC) $(CFLAGS) $(OBJS) -o $@
+
+$(OBJ)/%.o: $(SRC)/%.c
+	$(CC) $(CFLAGS) -c $< -o $@
 
 .PHONY: clean
 .PHONY: test
 
 clean:
-	rm -r obj
+	rm -r $(BINDIR)/* $(OBJ)/*
 
 test:
-	./obj/clox test.lox
+	$(BIN) test.lox