We generally document the suggested paths, not the paths possible in
weird, non-standard setups. We do this in order to not confuse
administrators/users unnecessarily and to push people to install things
into the same directories on all distributions.
We are PID 1 after all, the really basic building block of the OS.
Unlike for an app there's very little benefit in being entirely
relocatable.
- Consistent use of $VAR vs ${VAR}
- Consistent use of && vs 'if'
- Add error checking to some places
- Consistent error messages ("Can't" vs "Cannot", etc.)
- Function declarations at the top
- Miscellaneous adjustments
I typically run VMs with 1024MiB allocated; systemd is unable to write
coredumps in this scenario at all because the default kernel
configuration will only overcommit 50% of available RAM.
Avoid this failure by using a realloc() loop.
See: http://lists.freedesktop.org/archives/systemd-devel/2013-April/010709.html
Distributions may have selinux but not sushell or might
need to set a custom debug shell.
Defaults to /sbin/sushell if selinux is enabled, /bin/sh if not.
[zj: Renamed --with-debugshelltty to --with-debug-tty, and
added a line in output showing DEBUGSHELL and DEBUGTTY.
I figure that debug shell is pretty useful, and I hope
the extra line in configure status will draw attention
to it.]
clang emits warnings about unused attribute _saved_errno_, which drown
out other—potentially useful—warnings. gcc documentation is not exactly
verbose about the effects of __attribute__((unused)) on variables, but
let's assume that it works if the unit test passes.
gcc (and other compilers) sometimes generate spurious warnings, and
thus users of public headers must be able to disable warnings.
Printf format attributes can be disabled by setting
#define _sd_printf_attr_
before including the header file.
Also, add similar logic for sentinel attribute:
#define _sd_sentinel_attr_
before including the header file disables the attribute.
It is imperative that open source code be well attributed.
Sprinkle attribute((alloc_size)) here and there, telling gcc
how much memory we are actually allocating.
According to gcc documentation, returned pointer "cannot alias any
other pointer valid when the function returns" and "the memory has
undefined content". This second part is (hopefully) untrue for all
those functions.
