Re: cpphs (was Re: Haskell on Red Hat Enterprise...)

Malcolm Wallace wrote:

Andy Moran writes:

...

I notice that cpphs understands CPP stringification (if invoked with --hashes). Most of the gcc 3.4 failures (in fact, all of that I've seen) have to do with fooling -traditional into turning macro constants into Haskell strings, which can more readily be done with the #-operator. So, would using cpphs mean we could do away with the string gap hack?

Without seeing the examples in question, I can't say for definite, but cpphs /does/ preserve string gaps in source code in all cases.

Here's an example, from 6.2.1's ghc/utils/ghc-pkg/Main.hs: -- hackery to convice cpp to splice GHC_PKG_VERSION into a string version :: String version = tail "\ \ GHC_PKG_VERSION" HEAD uses a Makefile-generated Version.hs instead. Simon M.: are all instances of the above trick replaced by analogues of this much neater mechanism?

In addition, you can paste symbol values into strings using either the ANSI stringification operator (#) or the traditional behaviour of expansion within quotes ("SYMBOL").

So, cpphs' version of traditional is truer to tradition than gcc's, it seems. "gcc -E -traditional -x c" doesn't expand within quotes, which is why hacks like the above were introduced. Cheers, Andy -- Andy Moran Ph. (503) 626 6616, x113 Galois Connections Inc. Fax. (503) 350 0833 12725 SW Millikan Way, Suite #290 http://www.galois.com Beaverton, OR 97005 moran@galois.com