make project (somewhat) presentable

Makefile

@@ -1,16 +1,38 @@
-lua_sources = $(wildcard src/*.lua) $(wildcard src/cli/*.lua) $(wildcard src/formats/*.lua) $(wildcard src/util/*.lua)
-c_sources = lib/main.c lib/http.c lib/fmt.c lib/zlib.c
-target = dst/slimpack
-lua_target = dst/slimpack.h
+# requires lua, curl and zlib (in the future, lua will be statically linked)
+libraries := -llua -lcurl -lz
+flags := -Wall
+
+# lua is required in the build process, in order to compile the bytecode
+lua := lua
+cc := gcc
+
+dst_dir = dst
+src_lua_dir = src
+src_c_dir = lib
+
+# Uncomment to get debugging symbols
+# flags := -g
+
+lua_sources += $(wildcard $(src_lua_dir)/*.lua)
+lua_sources += $(wildcard $(src_lua_dir)/cli/*.lua)
+lua_sources += $(wildcard $(src_lua_dir)/formats/*.lua)
+lua_sources += $(wildcard $(src_lua_dir)/util/*.lua)
+
+c_sources = $(wildcard $(src_c_dir)/*.c)
+
+build_entry = $(src_c_dir)/build.lua
+
+target = $(dst_dir)/slimpack
+bytecode_target = $(dst_dir)/bytecode.h
 
 .PHONY: build
 
 build: $(target)
 
-./dst:
+$(dst_dir):
 	mkdir -p $@
 
-$(lua_target): $(lua_sources) ./dst
+$(bytecode_target): $(lua_sources) $(dst_dir)
 	lua lib/build.lua src $@ $(lua_sources)
-$(target): $(c_sources) $(lua_target) ./dst
-	gcc -g -Wall -include $(lua_target) $(c_sources) -o $@ -llua -lcurl -lz -Wall
+$(target): $(c_sources) $(bytecode_target) $(dst_dir)
+	gcc $(flags) $(libraries) -include $(bytecode_target) $(c_sources) -o $@