1 files changed, 32 insertions, 8 deletions
diff --git a/src/cljcc/cljcc.clj b/src/cljcc/cljcc.clj
index e687ae9..6708173 100644
--- a/src/cljcc/cljcc.clj
+++ b/src/cljcc/cljcc.clj
@@ -1,18 +1,42 @@
 (ns cljcc.cljcc
   (:require
+   [clojure.tools.cli :refer [parse-opts]]
+   [clojure.string :as string]
+   [cljcc.log :as log]
+   [cljcc.util :refer [exit]]
    [cljcc.driver :as d])
   (:gen-class))
 
 (set! *warn-on-reflection* true)
 
+(defn usage [options-summary]
+  (->>
+   ["Usage: ./cljcc path/to/file.c [options]"
+    ""
+    "Options:"
+    options-summary]
+   (string/join \newline)))
+
+(def cli-options
+  [[nil "--parse" "Runs parser. Does not emit any files."]
+   [nil "--codegen" "Runs compiler. Does not emit any files."]
+   ["-h" "--help"]])
+
+(defn validate-args [args]
+  (let [{:keys [options arguments summary]} (parse-opts args cli-options)]
+    (cond
+      (:help options) {:exit-message (usage summary) :ok? true}
+      (= 1 (count arguments)) {:file-path (first arguments)
+                               :options options}
+      :else {:exit-message (usage summary)})))
+
 (defn -main
   "Main entrypoint for cljcc compiler."
   [& args]
-  (let [input-file-path (first args)]
-    (try
-     (d/run input-file-path)
-     (catch Exception e
-       (println "Error: " (.getMessage e))
-       (System/exit 1))
-     (finally
-       (System/exit 0)))))
+  (let [{:keys [file-path exit-message ok? options]} (validate-args args)]
+    (if exit-message
+      (exit (if ok? 0 1) exit-message)
+      (try
+       (d/run file-path options)
+       (catch Exception e (exit 1 (.getMessage e)))
+       (finally (exit 0 "Succesfully ran compiler."))))))