multiarch: arch dependent header file path choice

[Osamu Aoki <osamu_aoki_home@nifty.com>]

Hi,

The path for the arch dependent header file seems to have several options.

 1) /usr/include/<multiarch>/*.h
 2) /usr/include/<multiarch>/<packagename>/*.h
 3) /usr/lib/<multiarch>/<packagename>/include/*.h

I would like to know rationale for each choice, especially between 2 and 3.

I am sure they all are functioning choice but intriguing to see choice 3.

(I was looking for the typedef of gsize in gobject header files in
/usr/include/glib-2.0.  It tool me time to find it in
/usr/lib/x86_64-linux-gnu/glib-2.0/include/glibconfig.h)

As I look around on my system, I observe followings

For 1, *.h are:
expat_config.h
ffi.h
ffitarget.h
fpu_control.h
gmp.h
ieee754.h
lua5.1-deb-multiarch.h
lua5.2-deb-multiarch.h
zconf.h

For 2, <packagename> are
python3.3m
openssl
ruby-2.0.0
c++
...

For 3, <packagename> are:
glib-2.0
gtk-2.0
gtk-3.0
dbus-1.0 (dbus/dbus-arch-deps.h as *.h)

Regards,

Osamu