[systemd-devel] [PATCH] Makefile.am: reduce linked libraries

[Daniel Drake]

Hi,

On Tue, Nov 1, 2011 at 4:39 PM, Lennart Poettering
<lennart at poettering.net> wrote:
> Hmm, let me see if I get this right: with this patch applied we'd build
> cap and selinux support into libsystemd-basic.la, but we wouldn't link
> against the respective libraries but instead do that in the binaries
> which pull in the .la?
>
> I am not sure I like this. I mean, I understand the goal, and it's a
> good one, but I think if we do this we should do this properly, and
> split up util.c so that the stuff that uses caps and selinux is
> independent of the rest and can be pulled in individually as needed.

This is true for the libcap case - libcap is only used by util.c so is
easy to split out.

But with selinux included, the task is more complicated. For example,
label.c (part of libsystemd-basic) also uses libselinux, so we need to
move it out somewhere else (lets say we put it in a new library:
libsystemd-extra). But the label_ functions are used several places
inside util.c itself. Things are tangled. If I were to go down this
path further I think we'd end up moving a huge amount of stuff to
libsystemd-extra.

Instead, do any of the following options make sense?

- Special-case systemd-timestamp because it's used in the initramfs.
Instead of linking against libselinux-basic just pull in util.c
directly into the compilation and link with -lrt.

- Create a new shared library used in compilation
(libsystemd-verybasic?), initially only containing the time-related
functions used by systemd-timestamp. Link systemd-timestamp against
that, and be happy.

- While linking executables (or immediately after), perform some
checks to see if the linked libraries are *really* necessary, and if
they aren't, drop the links. vim does this via the attached script.

Thanks,
Daniel