Re: msys : convert datadir to windows directory syntax

[Keith Marshall]

On Tuesday 04 September 2007 22:25, Ralf Wildenhues wrote:
> FWIW, just to set things a wee bit straighter: Autoconf "chose" to
> add the datarootdir indirection exactly because the GNU Coding
> Standards required this change.

Sure, I realise that; I don't have a problem with it.  My point was 
that, to effect this necessary change, the autoconf developers simply 
chose to modify certain internal definitions; the obvious solution 
really, and since the definitions affected had never been formally 
exposed as a documented interface, a perfectly legitimate change.

However, the *unofficial* AC_DEFINE_DIR macro had a built in dependency 
on these definitions, and became broken as a result of the change; just 
an illustration of the perils of relying on undocumented behaviour.

Of course, my own proposed solution to Vincent's original problem also 
relied, to a rather lesser extent, on some of the same undocumented 
features -- specifically that `$prefix' has a default value of `NONE' 
within `configure', if the user doesn't specify `--prefix=...', and 
that this default is replaced by the value of `$ac_default_prefix', 
when any eventual substitution is applied in any AC_OUTPUT file.

Sometimes, there is just no way to achieve an objective, without relying 
on some undocumented feature; when that is necessary, then it's best to 
keep the dependency to a minimum.

Regards,
Keith.