Re: One united Ada policy for all Linux distributions?

[Stephen Leake <stephen_leake@stephe-leake.org>]

Björn Persson <bjorn@xn--rombobjrn-67a.se> writes:

> Dmitry A. Kazakov wrote:
>
>> Ideally gpr files should be installed where GPS,
>> gprbuild, gnatmake could look after them. GNAT GPL's GPS does it in
>> <GNAT-root>/lib/gnat. I think the policy should mandate a directory under
>> /usr/lib or /usr/include for all gpr files rather than project-dependent
>> directories.
>
> The question of where to store .gpr files is actually rather complicated. 
> The .gpr file for a library needs to point to architecture-specific library 
> files, which makes the .gpr file itself architecture-specific if the 
> location is hard-coded. For example, a multilib system may have a 32-bit 
> /usr/lib/lib<library>.so with .ali files in /usr/lib/<library>/, and a 64-
> bit /usr/lib64/lib<library>.so with .ali files in /usr/lib64/<library>/. It 
> would then need two different .gpr files, one pointing to /usr/lib/<library> 
> and the other to /usr/lib64/<library>. 

I gather Debian will need to address this issue when we support multilib.

> One might then try putting the .gpr files somewhere in /usr/lib* too,
> for example /usr/lib/gnat/<library>.gpr and
> /usr/lib64/gnat/<library>.gpr. That doesn't work however, because
> although Gnat can be configured to look for .gpr files in multiple
> directories, it will look in the same set of directories regardless of
> whether it's compiling for 32-bit or 64-bit mode, and use the first
> .gpr file with a matching name that it finds. 

That's a bug, which I would expect to be fixed in a true multilib aware gnat. 

-- 
-- Stephe