iOS linker error UnityGetGLViewController()

Hi,

I'm very new to ios/objective-c development and am trying to build an ios plugin that adds things to the screen when triggered by unity. I'm having a strange issue when trying to access the view controller. When I call UnityGetGLViewController() from method2, everything builds and is peachy. But when called from method1, which is linked to the cs file in Unity, I get this linker error:

Undefined symbols for architecture armv7: "_UnityGetGLViewController", referenced from: _method1 in TestClass.o ld: symbol(s) not found for architecture armv7 clang: error: linker command failed with exit code 1 (use -v to see invocation)

Here is my code, stripped down for ease of reading:

 //TestClass.m
 
 #import "TestClass.h"
 extern UIViewController *UnityGetGLViewController();
 
 @implementation TestClass
 
 void method1(NSString* path){
     UIViewController *rootView = UnityGetGLViewController();
 }
 
 void method2(NSString* path){
     UIViewController *rootView = UnityGetGLViewController();
 }
 
 @end
 
 //iosPlugin.cs
 using UnityEngine;
 using System.Collections;
 using System.Runtime.InteropServices;
 
 public class iosPlugin : MonoBehaviour {
 
     [DllImport ("__Internal")]
     private static extern void method1 (string path);
 
     void Start () {
         method1("string here");
     }
 }

Any ideas as to why this is happening?