4.2 Project: "@file" support

[Mark Mitchell]

DJ Delorie wrote:
>>feature even on Unix systems.  But on Unix systems I think we need to
>>at least consider the possibility of real source file names starting
>>with '@'.  The patch as it stands will have a rather perplexing effect
>>if such a file is compiled.  Maybe that's OK.
> 
> This is different from Mark's patch in that Mark's patch will cause
> the application to exit when some @string doesn't reflect a response
> file.

I'm not wedded to any of the technical details in my patch.  If we get 
to the point where all we have to do is agree on exactly how to handle 
these kinds of things, I would consider that a victory!

I based my implementation on some experimentation with MSVC and on 
reading the Microsoft documentation.  But, I wouldn't claim that I 
exhaustively matched the behavior; it wasn't well enough documented, and 
I didn't experiment heavily enough.

If a condition for acceptance is making "@string" silently accepted if 
"string" is not a file, for example, I'll happily implement that.

-- 
Mark Mitchell
CodeSourcery, LLC
mark@codesourcery.com
(916) 791-8304