[csw-maintainers] Using an architecture-specific includes in GAR

[Dagobert Michelsen]

Hi folks,

Am 05.08.2011 um 09:15 schrieb Maciej Bliziński:
> Suppose I have a package which has different headers for different
> architectures (e.g. libgmp).  What's the best place for the headers?
> Is the following sane?
> 
> /opt/csw/include/amd64 d none 0755 root bin CSWlibgmp-dev
> /opt/csw/include/amd64/gmp.h f none 0644 root bin 86215 39079
> 1312523810 CSWlibgmp-dev
> /opt/csw/include/gmp.h f none 0644 root bin 86204 38065 1312523796 CSWlibgmp-dev
> /opt/csw/include/pentium d none 0755 root bin CSWlibgmp-dev
> /opt/csw/include/pentium/gmp.h f none 0644 root bin 86208 38680
> 1312523801 CSWlibgmp-dev
> 
> Second question: Is there an idiom in GAR that automatically pick the
> right include file? For example, when I'm building for amd64, I want
> the /opt/csw/include/amd64 directory to be first in the include search
> path. I know I can fiddle with EXTRA_INC in my build description, but
> perhaps there's already something in the GAR code to handle this case.

(I'll get back on monday, just a quick heads up for now, haven't checked
any other emails)

The includes can usually be branched by compile-specific flags for the
ISA to compile. One notable example for this is curlbuild.h which contains
isa-specific definitions of different wide types when compiled on 32 and
64 bits. Traditionally, this has been done by a rename of isa-specific
headers and a meta-header with the branch:
  http://sourceforge.net/apps/trac/gar/browser/csw/mgar/pkg/curl/tags/curl-7.20.0%2CREV%3D2010.02.15/Makefile#L72
  http://sourceforge.net/apps/trac/gar/browser/csw/mgar/pkg/curl/tags/curl-7.20.0%2CREV%3D2010.02.15/files/curlbuild.h

After that I found out that there is a specific diff-mode which can
generate define-shielded diffs in C header format to make just one
unified diff:
  http://sourceforge.net/apps/trac/gar/browser/csw/mgar/pkg/libcurl4/trunk/Makefile#L157
(this was "lend" from some recipe from the OpenSolaris contrib tools tree).

I plan to introduce that automatically in GAR to always diff like this between
isa-default-32 and isa-default-64 headers which will usually yield in just
the 32 bit default headers being the same without any branching.


Best regards

  -- Dago


-- 
"You don't become great by trying to be great, you become great by wanting to do something,
and then doing it so hard that you become great in the process." - xkcd #896