Re: V3 and Integrated CPP [was Re: V3 PATCH: Disable wide-character tests where necessary]

[Jamie Lokier <egcs at tantalophile dot demon dot co dot uk>]

Neil Booth wrote:
> >   1. When using --save-temps, use cpp output routines to write the .i
> >      file while passing the tokens directly to cc1.
> >
> >   2. Invoke cpp to generate the .i file, then do it again for
> >      compilation as usual.
> 
> Yes, either of these should be possible.  2 is of course the simplest.

With 2 the input files might be different the second time around.  This
isn't an issue is it?

> >   3. Position tokens in the .i file such that they are at the correct
> >      column numbers.  This would be useful for other programs too.
> 
> If I understand your meaning, this isn't possible - a macro can expand
> arbitrarily wide.

It's possible but makes prohibitively large files.  (Though most of the
below is to get the right line numbers, the right columns are a
relatively small cost).

example.c:

#define DOUBLE(x) (2*(x))
i = DOUBLE (i);

example.i:

#line 2 "example.c"
i =
#line 1 "example.c"
                  (2*(
#line 2 "example.c"
            i
#line 1 "example.c"
                       ))
#line 2 "example.c"
              ;


enjoy,
-- Jamie