Before, we would initialize many fields twice: first
by filling the structure with zeros, and then a second
time with the real values. We can let the compiler do
the job for us, avoiding one copy.
A downside of this patch is that text gets slightly
bigger. This is because all zero() calls are effectively
inlined:
$ size build/.libs/systemd
text data bss dec hex filename
before 897737 107300 2560 1007597 f5fed build/.libs/systemd
after 897873 107300 2560 1007733 f6075 build/.libs/systemd
… actually less than 1‰.
A few asserts that the parameter is not null had to be removed. I
don't think this changes much, because first, it is quite unlikely
for the assert to fail, and second, an immediate SEGV is almost as
good as an assert.
If people are unaware or uninterested in the concept of pretty host
names, and simply invoke "hostnamectl set-hostname" for a valid internet
host name, then use this as indication to unset the pretty host name and
only set the static/dynamic one.
This also allows fqdn, hence "hostnamectl set-hostname www.foobar.com"
will just work if people really insist on using fqdns as hostnames.
For many usecases it is useful to store the chassis type somewhere, and
/etc/machine-info sounds like a good place. Ideally we could always
detect the chassis type from firmware, but frequently that's not
available and in many embedded devices probably entirely unrealistic.
This patch adds a configurable setting CHASSIS= to /etc/machine-info and
exposes this via hostnamectl/hostnamed. hostnamed will guess the chassis
type from DMI if nothing is set explicitly. I also added support for
detecting it from ACPI, which should be more useful as ACPI 5.0 actually
knows a "tablet" chassis type, which neither DMI nor previous ACPI
versions knew.
This also enables DMI-based and ACPI-based detection for non-x86 systems
as ACPI is apparently coming to ARM platforms soon.
I tried to minimize the vocabulary of chassis types understood and
added: desktop, laptop, server, tablet, handset. This is much less than
either APCI or DMI know. If we need more types later on we can easily
add them.
