Controlling -fno-unit-at-a-time

Duncan Coutts duncan.coutts at
Thu Oct 5 08:29:38 EDT 2006

On Thu, 2006-10-05 at 10:55 +0100, Simon Marlow wrote:
> Ian Lynagh wrote:
> > On Tue, Oct 03, 2006 at 04:59:58PM -0400, Ravi Nanavati wrote:
> > 
> >>If I understand the way things work, GHC decides whether or not to emit 
> >>the -fno-unit-at-a-time flag in -fvia-C compilation based on whether or 
> >>not the gcc used when compiling GHC supported the flag or not. I'm 
> >>running into trouble using precompiled GHC snapshots (that were compiled 
> >>on machines whose gcc supports -fno-unit-at-a-time) on a machine whose 
> >>gcc doesn't support it (a gcc 3.2 version, I believe).
> >>
> >>Is there any way force GHC to not emit the flag (short of recompiling 
> >>from source)?

> It would be nice if these kind of configuration settings were in some file 
> rather than being baked into GHC.  I think it might be possible to pass in these 
> flags via the package configuration for the rts package, for example.

A few months back I looked at doing just this. Having a ghc-reconf tool
that would update the flags in the rts package to reflect the current
environment (basically the gcc version). I didn't finish it but my code
is still around so if anyone wants to pick it up just ask me.


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