darcs patch: Add initial support for --enable/disable-library-vanilla

[Simon Marlow]

Duncan Coutts wrote:
> On Fri, 2006-07-28 at 11:30 -0700, Isaac Jones wrote:
> 
> 
>>>>The TH thing - can we check that this is really the right thing to do?
>>>>
>>>>So the code is forcing normal libs to be built when the library uses TH
>>>>(even if the user didn't want to build normal libs).
>>>>
>>>>Note that they've not got a fix for this yet in GHC:
>>>>
>>>>http://www.haskell.org/pipermail/template-haskell/2003-July/000135.html
>>>>http://www.haskell.org/pipermail/template-haskell/2005-July/000466.html
>>>>
>>>>http://hackage.haskell.org/trac/ghc/ticket/651
>>>>
>>>>So we should check with the GHC devs that the behaviour in this patch
>>>>will need to be part of any solution. Otherwise it seems a bit
>>>>preemptive.
>>>
>>>Since no one said anything I've committed the patch but without the TH
>>>bit and with some other minor changes.
>>
>>OK. I've CC'd Simon so he can lend is $0.02 about the TH stuff.
> 
> 
> I caught Simon on irc the other day and he thought that this sounds like
> the right behaviour.
> 
> Specifically: if the user asks for profiling but not vanilla versions of
> libs and they're using TH then we should build vanilla libs first and
> then profiling libs. However at install time we would not install the
> vanilla libs as the user did not ask for them.

Yes, that's right.

> Simon: what about if we're building a program rather than a lib? Should
> we vanilla-compile all the modules but not link then into a binary and
> then compile again with profiling and then link those into a binary?

I would think so, yes.  Just build with --make -c for the vanilla way.

> And presumably we would only expect this to work with GHC 6.6.

Yes.  I'd appreciate it if someone could test this with a TH program and 6.6, to 
make sure that GHC can find the vanilla object files correctly.

Cheers,
	Simon