PATCH: Support "@file"

[Nick Clifton]

Hi Mark,

>>  * The @<file> syntax cannot be used inside the file being parsed.
> 
> The second point is actually not true; DJ asked that I make it support
> recursion. 

Oops - I looked at the code in libiberty but I must have missed that. 
Sorry.


> @item @@@var{file}
> Read command-line options from @var{file}.  The options read are
> inserted in place of the original @@@var{file} option.  If @var{file}
> does not exist, or cannot be read, then the option will be treated
> literally, and not removed.
> 
> Options in @var{file} are separated by whitespace.  A whitespace
> character may be included in an option by surrounding the entire
> option in either single or double quotes.  Any character (including a
> backslash) may be included by prefixing the character to be included
> character with a backslash.  The @var{file} may itself contain
> additional @@@var{file} options; any such options will be processed
> recursively.

This is excellent - thanks very much.


>>  --extra-switches-from-file=<file>

> If we do it, I think we should do that in the existing expandargv.  That
> will ensure it's consistent across all programs which use expandargv,
> which seems like a good thing.

Agreed - DJ - do you think that this is a good idea ?  I can submit a 
patch for exandargv if you like.

Cheers
   Nick

PS.  Mark - is @file support going to be added to GCC as well ?