On 09 August 2005 11:23, Ross Paterson wrote:
On Tue, Aug 09, 2005 at 09:02:50AM +0100, Simon Marlow wrote:
On 08 August 2005 16:57, Jonathan Cast wrote: [Simon wrote:]
--bindir=<dir> --libdir=<dir> --datadir=<dir>
where the values of these would be directories relative to $prefix (or absolute? relative to $prefix seems nicer).
Relative paths here break compatibility with Autoconf; when I install a program, I don't care where its configure script comes from, I just want to be able to invoke it the way I expect to. Gratuitous incompatibilities between configure scripts is very inconvenient.
I do agree, and I half-expected someone to point out the inconsistency. OTOH, this isn't a "configure script", it's the Setup.lhs program. You already have to know that it isn't an autoconf configure script, because it has different syntax.
Another incompatibility is that configure has options --datadir etc with a different meaning to yours. I think yours should be renamed; we might want the autoconf-style ones too.
Really? I intended them to work in the same way. What differences are you referring to? If you think this is a generalisation too far, I guess I could live with having fixed values for all these, but they should be relative to $prefix, and that still leaves us with Krasimir's complaint about the default $bindir/$libdir on Windows.
One reason I suggested that relative paths would be better is because it allows you to build a binary/library that is prefix-independent, at least on Windows where a binary knows the absolute $bindir and hence can derive $prefix because it knows $bindir relative to $prefix.
What would the code in the packaged program look like? It seems you'd want some library support for this.
I suppose you'd have something like this: getPrefix :: FilePath -- bindir relative to prefix -> FilePath -- returns prefix but it only works on Windows. GHC, Happy, Alex and Haddock all have something like this internally (but bindir is either fixed or assumed to be equal to $prefix right now). From prefix you can get libdir and datadir, if these are also specified relative to prefix.
And what if the builder modified bindir?
If the builder can modify bindir, the program gets the value from paths.h (or whatever mechanism we choose). Cheers, Simon