asprintf is nice to use, but the _documented_ error return convention is
unclear:
> If memory allocation wasn't possible, or some other error occurs,
> these functions will return -1, and the contents of strp are undefined.
What exactly "undefined" means is up for debate: if it was really
undefined, the caller wouldn't be able to meaningfully clean up, because
they wouldn't know if strp is a valid pointer. So far we interpreted
"undefined" — in some parts of the code base — as "either NULL or a
valid pointer that needs to be freed", and — in other parts of the
codebase — as "always NULL". I checked glibc and musl, and they both
uncoditionally set the output pointer to NULL on failure.
There is also no information _why_ asprintf failed. It could be an
allocation error or format string error. But we just don't have this
information.
Let's add a wrapper that either returns a good string or a NULL pointer.
Since there's just one failure result, we don't need a separate return
value and an output argument and can simplify callers.
Let's define a way how to mark codepaths that are subject to
deletion once the kernel baseline reaches a certain version, to make it
easier to find these cases.
WHile we are at it, introuce a whole section in CODING_STYLE about
kernel version compat.
I followed the new scheme in #39621, but we can merge the coding style
guidelines on this already.
When a TTY is attached to the test unit, grep -q will generate SIGPIPE
for the previous command in the pipeline which in combo with `pipefail`
will cause the command to fail with exit status 141 which will fail the
test.
Replace with >/dev/null to avoid this from happening.
See also https://www.gnu.org/software/grep/manual/html_node/Usage.html
> There is a related problem with Bash’s set -e -o pipefail. Since grep
> does not always read all its input, a command outputting to a pipe read
> by grep can fail when grep exits before reading all its input, and the
> command’s failure can cause Bash to exit.
Co-authored-by: Yu Watanabe <watanabe.yu+github@gmail.com>
Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
In preparation for adopting forward declarations to reduce unnecessary
transitive includes across the tree, let's introduce a forward.h header
with forward declarations for all libc, libsystemd, basic and shared types.
Additionally, this header exports all basic integer types and errno constants,
as well as all macros including assertions macros. These header files contain
types often used in headers and are always included in every source file one
way or another anyway.
To avoid having to include memory-util.h and alloc-util.h in forward.h, we
split off the parts we need from both into cleanup-util.h and only include
cleanup-util.h in forward.h.
To keep this commit self-contained, we include cleanup-fundamental.h and
cleanup-util.h from the headers that originally contained the same macros.
We'll remove these again in a later commit that optimizes the includes in
src/basic and src/fundamental.
Split out of #37364
In some recent PRs (e.g. #32628) I started to systematically name return
parameters that shall only be initialized on failure (because they carry
additional error meta information, such as the line/column number of
parse failures or so). Let's make this official in the coding style.
This reverts commit 5e8ff010a1.
This broke all the URLs, we can't have that. (And actually, we probably don't
_want_ to make the change either. It's nicer to have all the pages in one
directory, so one doesn't have to figure out to which collection the page
belongs.)
… but only for a single variable.
The guidelines already allowed declaring variables at the point of
initialization. But not making a function call to do that. Let's allow that
now. The existing style of declaring and initializing seperate is still
allowed, and whatever makes most sense should be used.
I have no idea if this is going to cause rendering problems, and it is fairly
hard to check. So let's just merge this, and if it github markdown processor
doesn't like it, revert.
Zbigniew Jędrzejewski-Szmek
Yu Watanabe
Lennart Poettering
Lennart Poettering
DaanDeMeyer
Mike Yuan
Zbigniew Jędrzejewski-Szmek
hulkoba
Dmitry V. Levin
Sam James
bearhoney
Erik Sjölund
Emily Gonyer