[nhc-users] Problem installing nhc98 1.16 using bootstrap-from-C method

Malcolm Wallace Malcolm.Wallace@cs.york.ac.uk
Thu, 10 Apr 2003 18:40:17 +0100


"David Bakin" <davidbak@attbi.com> writes:

> Got it working with that fix - although I couldn't get the nhc98 -C step to
> work to compile the fixed .hs file (it complained about not finding
> Platform.hi in any of several locations, even after a full successful build
> there is still no Platform.hi anywhere - should there be?)

I now see that RunAndReadStdout imports Platform, so you would have
needed to nhc98-compile the latter to generate a .hi file before you
could successfully nhc98-compile the former.  The .hi files are not
needed when bootstrapping via C, but of course the Haskell compiler
itself requires them (and generates them).

> I have another question though:  on the "Building/Installing nhc98" page it
> says that if you build using the C compiler only the resulting compiler is
> slower.  Why?

The C-bootstrapped compiler is exactly the nhc98 compiler built with
itself.  Any program built by nhc98 runs on average 4-5x slower than
the same program built by ghc - this is the usual tradeoff between
space and speed optimisations.

> Anyway, now that I have built from C sources should I bootstrap
> through the resulting nhc98?

I wouldn't recommend it.  You will end up with an identical compiler,
but spend a lot of time getting there!

> Plus a small correction for the "Installing nhc98 under Windows" page:  you
> also need cygwin's 'bc' tool which is not installed by default.

I don't recall using 'bc' anywhere in the build scripts - can you
let me know the location where you needed it please?

Regards,
    Malcolm