<p>When I try to precompile a *.pc file that contains a #warning directive I recieve the following error:</p>

<blockquote>
  <p>PCC-S-02014, Encountered the symbol "warning" when expecting one of the following: (bla bla bla).</p>
</blockquote>

<p>Can I somehow convince Pro*C to ignore the thing if it doesn't know what to do with it? I can't remove the <code>#warning</code> directive as it's used in a header file that I can't change and must include.</p>

You can't.  Pro*C only knows #if and #include.  My best advice would be to preprocess the file as part of your build process to remove stuff Pro*C won't like.  Something like
```
```
grep -v -E '^#(warning|pragma|define)' unchangeable.h >unchangeable.pc.h
```
```
My other advice would be to avoid the abomination which is Pro*C, but I'm guessing you're stuck with it...