This splits out a bunch of functions from fileio.c that have to do with
temporary files. Simply to make the header files a bit shorter, and to
group things more nicely.
No code changes, just some rearranging of source files.
This is really basic stuff and in a follow-up commit will use it all
across the codebase, including in process-util.[ch] which is in
src/basic/. Hence let's move it back to src/basic/ itself.
This doesn't have much effect on the final build, because we link libbasic.a
into libsystemd-shared.so, so in the end, all the object built from basic/
end up in libsystemd-shared. And when the static library is linked into binaries,
any objects that are included in it but are not used are trimmed. Hence, the
size of output artifacts doesn't change:
$ du -sb /var/tmp/inst*
54181861 /var/tmp/inst1 (old)
54207441 /var/tmp/inst1s (old split-usr)
54182477 /var/tmp/inst2 (new)
54208041 /var/tmp/inst2s (new split-usr)
(The negligible change in size is because libsystemd-shared.so is bigger
by a few hundred bytes. I guess it's because symbols are named differently
or something like that.)
The effect is on the build process, in particular partial builds. This change
effectively moves the requirements on some build steps toward the leaves of the
dependency tree. Two effects:
- when building items that do not depend on libsystemd-shared, we
build less stuff for libbasic.a (which wouldn't be used anyway,
so it's a net win).
- when building items that do depend on libshared, we reduce libbasic.a as a
synchronization point, possibly allowing better parallelism.
Method:
1. copy list of .h files from src/basic/meson.build to /tmp/basic
2. $ for i in $(grep '.h$' /tmp/basic); do echo $i; git --no-pager grep "include \"$i\"" src/basic/ 'src/lib*' 'src/nss-*' 'src/journal/sd-journal.c' |grep -v "${i%.h}.c";echo ;done | less
As preparation for OCI support in nspawn, let's add a JSON parser.
The json.h file contains an explanation why this is new code instead of
just us linking against an existing JSON library.
Unfortunately this needs libshared to link to libkmod. Before it was linked
into systemd-udevd, udevadm, and systemd each seperately. On most systems this
doesn't make much difference, because at least systemd would be installed, but
it might not be in small chroots. It is a small library, so I hope this is not
a big issue.
This means that when those targets are built, all the sources are built again,
instead of reusing the work done to create libbasic.a and other convenience static
libraries. It would be nice to not do this, but there seems to be no support in
our toolchain for joining multiple static libraries into one. When linking
a static library, any -l arguments are simply ignored by ar/gcc-ar, and .a
libraries given as positional arguments are copied verbatim into the archive
so they objects in them cannot be accessed.
https://stackoverflow.com/questions/2157629/linking-static-libraries-to-other-static-libraries
suggests either unzipping all the archives and putting them back togather,
or using a linker script. Unzipping and zipping back together seems ugly.
The other option is not very nice. The linker script language does not
allow "+" to appear in the filenames, and filenames that meson generates
use that, so files would have to be renamed before a linker script was used.
And we would have to generate the linker script on the fly. Either way, this
doesn't seem attractive. Since those static libraries are a niche use case,
it seems reasonable to just go with the easiest and safest solution and
recompile all the source files. Thanks to ccache, this is probably almost as
cheap as actually reusing the convenience .a libraries.
test-libsystemd-sym.c and test-libudev-sym.c compile fine with the generated
static libs, so it seems that they indeed provide all the symbols they should.
We have plenty of code in our codebase that outputs tables to the
console, and all is homegrown and awful. Let's replace it with a generic
implementation that can do automatically what the old implementations
did manually.
Features:
1. Ellipsation (for fields overly long) and alignment (for
fields overly short)
2. Sorting of rows
3. automatically copies formatting from the same cell in the row above
4. Heavy use of varargs to make putting together tables easy
5. can expand and compress tables, with weights
6. Has a minimal understanding of unicode wide characters in order to
match unicode strings to character cell terminals.
7. Columns can be reordered and individually turned off.
8. pretty printing for various data types
And more.
pager.[ch] doesn't use any APIs from src/libsystemd/ or src/shared/
hence there's no reason for it to be in src/shared/, let's move it to
src/basic/ instead.
This enables us to use pager.[ch] APIs from other code in src/basic/,
for example pager_have() and suchlike.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This is primarily preparation for a follow-up commit that adds a common
implementation of the other side of the reboot parameter file, i.e. the
code that reads the file and issues reboot() for it.
This mimics the raw_clone() call we have in place already and
establishes a new syscall wrapper raw_reboot() that wraps the kernel's
reboot() system call in a bit more low-level fashion that glibc's
reboot() wrapper. The main difference is that the extra "arg" argument
is supported.
Ultimately this just replaces the syscall wrapper implementation we
currently have at three places in our codebase by a single one.
With this change this means that all our syscall() invocations are
neatly separated out in static inline system call wrappers in our header
functions.
