use go generate over Makefile

pkg/mumbleproto/generate_main.go

@@ -0,0 +1,49 @@
+// +build ignore
+
+package main
+
+import (
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os/exec"
+	"regexp"
+)
+
+var replacements = []string{
+	`(?m)^package MumbleProto;$`, `package mumbleproto;`,
+	`(?m)^(message Version {)$`, "$1\n\trepeated string crypto_modes = 5;\n",
+}
+
+func main() {
+	// Fetch Mumble.proto
+	resp, err := http.Get("https://raw.githubusercontent.com/mumble-voip/mumble/master/src/Mumble.proto")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer resp.Body.Close()
+	data, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Perform replacements
+	for i := 0; i < len(replacements); i += 2 {
+		re, rp := replacements[i], replacements[i+1]
+		regex, err := regexp.Compile(re)
+		if err != nil {
+			log.Fatal(err)
+		}
+		data = regex.ReplaceAll(data, []byte(rp))
+	}
+
+	// Write Mumble.proto
+	if err := ioutil.WriteFile("Mumble.proto", data, 0644); err != nil {
+		log.Fatal(err)
+	}
+
+	// Run protobuf compiler
+	if err := exec.Command("protoc", "--go_out=.", "Mumble.proto").Run(); err != nil {
+		log.Fatal(err)
+	}
+}