title: Is it possible to define a label using contents of another label in NASM?
body: <p>Consider the following code:</p>
  
  <pre><code>    section .data
  bar:        db 'bar'        ; label bar
  foo_bar:    db 'foo', bar   ; label foo_bar
  </code></pre>
  
  <p>The above code when assembled using NADM under Mac OS X will give the following error:</p>
  
  <pre><code>error: Mach-O 64-bit format does not support 32-bit absolute addresses
  </code></pre>
  
  <p>I know that labels refer to some absolute address in the memory, does this mean I need to calculate the absolute 64-bit address of bar? or perhaps I should calculate the relative address of bar? What's going wrong here? Or if I'm using a wrong approach, then how two create a label using contents of another label.</p>
  
  <p>I'm on Mac OS X 10.10. I have a core i5 m540 Intel CPU. I use NASM version 2.11.06.</p>