From bd352d81f37deee1d1a4b88d5b0eeba153d15964 Mon Sep 17 00:00:00 2001
From: otya128 <otya128@users.noreply.github.com>
Date: Sun, 4 Dec 2016 16:30:31 +0900
Subject: [PATCH] Add Undefined Label Error

---
 SMILEBASIC/compiler.d | 14 ++++++++++++--
 SMILEBASIC/error.d    | 12 ++++++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/SMILEBASIC/compiler.d b/SMILEBASIC/compiler.d
index ab53a6e..5b3d6cd 100644
--- a/SMILEBASIC/compiler.d
+++ b/SMILEBASIC/compiler.d
@@ -1167,11 +1167,21 @@ class Compiler
                 auto label = cast(GotoS)c;
                 if(label.sc.func)
                 {
-                    code[i] = new GotoAddr(label.sc.func.label[label.label]);
+                    int addr = label.sc.func.label.get(label.label, int.min);
+                    if (addr == int.min)
+                    {
+                        throw new UndefinedLabel(label.label);
+                    }
+                    code[i] = new GotoAddr(addr);
                 }
                 else
                 {
-                    code[i] = new GotoAddr(globalLabel[label.label]);
+                    int addr = globalLabel.get(label.label, int.min);
+                    if (addr == int.min)
+                    {
+                        throw new UndefinedLabel(label.label);
+                    }
+                    code[i] = new GotoAddr(addr);
                 }
             }
             if(c.type == CodeType.GosubS)
diff --git a/SMILEBASIC/error.d b/SMILEBASIC/error.d
index 2a24483..f4c622a 100644
--- a/SMILEBASIC/error.d
+++ b/SMILEBASIC/error.d
@@ -96,6 +96,18 @@ class OutOfDATA : SmileBasicError
         super("Out of DATA");
     }
 }
+class UndefinedLabel : SmileBasicError
+{
+    this()
+    {
+        this.errnum = 14;
+        super("Undefined label");
+    }
+    this(wstring label)
+    {
+        this();
+    }
+}
 class UndefinedVariable : SmileBasicError
 {
     this()