Add basic logging.

Author: manpreeeeeet

frame.go

@@ -6,7 +6,7 @@ import (
 
 type Frame struct {
 	stack              []interface{}
-	localVariables     []interface{} // function parameters basically
+	localVariables     []interface{}
 	code               []byte
 	instructionPointer uint32
 	class              *Class

jvm.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"errors"
+	"fmt"
+	"log"
 	"os"
 )
 
@@ -60,5 +62,18 @@ func (jvm *JVM) executeMethod(className string, methodName string, methodDescrip
 	frame := code.toFrame(class, args...)
 	result := jvm.Exec(&frame)
 
+	argString := ""
+	for i, arg := range args {
+		if i > 0 {
+			argString += ","
+		}
+		switch arg.(type) {
+		case *Object:
+			argString += "this"
+		default:
+			argString += fmt.Sprintf("%v", arg)
+		}
+	}
+	log.Printf("%s.%s(%s) --> %v\n", className, methodName, argString, result)
 	return result, nil
 }

main.go

@@ -1,5 +1,10 @@
 package main
 
+import (
+	"fmt"
+	"log"
+)
+
 func main() {
 	jvm := JVM{classes: make([]*Class, 0)}
 	_, err := jvm.addClass("Main")
@@ -8,7 +13,10 @@ func main() {
 	}
 	_, err = jvm.executeMethod("Main", "main", "([Ljava/lang/String;)V")
 	if err != nil {
+		fmt.Printf("JVM failed with error %v", err)
 		return
 	}
 
+	log.Println("JVM exited successfully.")
+
 }