title: how to use __irq keyword in clang cross compile (ARM)
body: <p>I am trying to cross-compile a cortex-r7 arm application on an x86 system (ubuntu). The compiler is clang.
  I was wondering what options should be given to compile interrupt routines marked with __irq keyword.</p>
  <p>The options currently in use are:</p>
  <pre><code>clang -c -std=c99 -target arm-none-linux-gnueabi -mcpu=cortex-r7
  </code></pre>
  <p>The isr function to compile is as follows.</p>
  <pre><code>void __isr Handler(void) { ... }
  </code></pre>