Re: [sdcc-devel] New cpp comitted

[Kevin V. <ke...@vi...>]

On 05-Jul-2001 Johan Knol wrote:
> It works perfectly for me, but doesn't solve bug #435127

Actually, #435127 is not a bug, though it pointed some out.

Firstly, the result of the '##' macro operator must be a valid
preprocessing token. '//' is not a valid pre-processing token. According
to the ISO spec 6.10.3.3.3, the result of this is undefined; the new cpp
throws a warning and outputs the two tokens seperated by a space (which
is admittedly odd, but is what gcc 3.0 does (and is not what earlier revs
of gcc did)). The old cpp got into a deeply confused state and threw
everything away with no warning.

Secondly, even if it did work as expected (which it isn't required by the
spec to do), the result would be a syntax error; comments are required to
be removed before macro substitutions, not after, so you'd end up passing
'//' into the lexer, which would choke.

        Peace,
                Kevin