\s at the end of lines and cpp

[Ian Lynagh]

Hi guys,

Presumably as one of the gcc 3.3 changes, cpp now treats all '\'s at the
end of a line as a line continuation character (at least I imagine
that's what is happening, but it doesn't seem to be actually eating a
'\n').

This means that when Helium says

    infixl 9 \\

in ../../lvm/src/lib/common/Set.hs, which is compiled with -cpp, ghc
says

    ../../lvm/src/lib/common/Set.hs:137: parse error on input `\'

as it is seeing

    infixl 9 \

Adding a ';' to the end of the line is one way to fix this.

I'm not sure if the GHC guys consider this a bug; it could possibly be
worked around by protecting trailing '\'s (just appending a space is
sufficient) on lines cpp shouldn't be looking at, but for macro calling
lines that might not be possible.


Thanks
Ian