title: Update to Xcode 6.3 breaks app - Google GTLTouchStaticLib "not equal to a null pointer is always true"
body: <p>I use Google Drive SDK in my app. </p>
  
  <p>It has worked perfectly since around June 2014.</p>
  
  <p>Following update to Xcode 6.3, none of my targets build.</p>
  
  <p>The implementation file <strong>GTMOAuth2ViewControllerTouch.m</strong> contains two blocks that the compiler complains about:</p>
  
  <pre><code>if (accessibility == NULL
      &amp;&amp; &amp;kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly != NULL) {
          accessibility = kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly;
  }
  </code></pre>
  
  <p>specifically with the message: "Comparison of address of <code>kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly</code> not equal to a null pointer is always true".</p>
  
  <p>AND</p>
  
  <pre><code>if (accessibility != NULL &amp;&amp; &amp;kSecAttrAccessible != NULL) {
      [keychainQuery setObject:(id)accessibility
                        forKey:(id)kSecAttrAccessible];
  }
  </code></pre>
  
  <p>specifically with the message: "Comparison of address of <code>kSecAttrAccessible</code> not equal to a null pointer is always true".</p>
  
  <p>The compiler is telling me that the two keys when compared to <code>!= NULL</code> is always true.</p>
  
  <p>I believe my lack of computer science training leaves me unable to understand the issue here - maybe that is just a bad perception?</p>
  
  <p>I've had a look at <a href="https://stackoverflow.com/questions/29559430/open-settings-warning-issue-in-xcode-6-3-comparison-of-address-of-uiapplicatio">this question</a> but cannot understand the context in relation to my problem with Google Drive SDK implementation file GTMOAuth2ViewControllerTouch.m</p>
  
  <p>I'd really like to understand the underlying issue.</p>
  
  <p>Please help...</p>