multilib fun - devel packages

[Ralf Corsepius]

On Fri, 2005-12-09 at 08:42 +0000, Joe Orton wrote:
> On Fri, Dec 09, 2005 at 03:19:14AM -0500, Jakub Jelinek wrote:

> > If the only differences are wordsize related, you can e.g.
> > portably #include <limits.h> and do:
Well, agreed, this is the by far the most common case as far as
ix86/x86_64 are concerned, but I've seen such issues with packages
trying to export all kind of system/compiler characteristics, comprising
byte alignment, page size, inline asm-macros etc.

> The differences are generally because the entire header is 
> autoconf-generated so really the whole thing would have to be renamed 
> for each platform and an #if/#include stub put in its place.  This is 
> feasible but ugly and upstream would have little interest in maintaining 
> such hacks (it's not as if I've ever heard any user cry out for this 
> "problem" to be solved).
Well, you might not have heard about it, probably because your primary
target is non-multilib'ed - Users and developers on multilib'ed targets
are used to complain about it and having to cope with it ;)
[A well known example: lack of multilibs in GNAT (GCC Ada, libada).]

Wrt. to autoconf, this topic (Exporting config-headers) comes up on the
autoconf mailing list at a regular basis, ca. once per year. So it's not
as uncommon as you might think.

The answer template to this kind of questions on the autoconf list is:
You are abusing the autotools. Auto-headers are not supposed to be
exported. 

As Jakub already pointed out, solutions often are pretty simple, unless
a package's API (We are talking about headers) is utterly mal-designed. 

Ralf