This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
Let's include the command line to use to get the requested output. This
makes it easy to copy/paste the command line out, and add "--in-place"
to actually apply the changes "run-coccinelle.sh" outputs.
At various places we only want to close fds if they are not
stdin/stdout/stderr, i.e. fds 0, 1, 2. Let's add a unified helper call
for that, and port everything over.
It doesn't work, spits out only rubbish and was already excluded of
run-coccinelle.sh. It's a pitty it doesn't work, but let's drop this
dead piece of code for now.
Apparently O_NONBLOCK is the modern name used in most documentation and
for most cases in our sources. Let's hence replace the old alias
O_NDELAY and stick to O_NONBLOCK everywhere.
On Linux the former is a compat alias to the latter, and that's really
weird, as inside the kernel the two are distinct. Which means we really
should stay away from it.
With these additions, coccinelle finds everything fixed by the first
commit in PR #7695. In order not to needlessly conflict with that PR
this PR won't include those fixes, but only the coccinelle changes to
detect them automatically in the future.
This makes things a bit easier to read I think, and also makes sure we
always use the _unlikely_ wrapper around it, which so far we used
sometimes and other times we didn't. Let's clean that up.
Our CODING_STYLE suggests not comparing with NULL, but relying on C's
downgrade-to-bool feature for that. Fix up some code to match these
guidelines. (This is not comprehensive, the coccinelle output for this
is unfortunately kinda borked)
IN_SET only works for constant values, hence clarify that. Moreover, we
declared a statement "s" we never made use of. Drop it.
Also, for both scripts, let's support 10 items. More causes spatch to
die with "Stack overflow" for me.
It's a common pattern, so add a helper for it. A macro is necessary
because a function that takes a pointer to a pointer would be type specific,
similarly to cleanup functions. Seems better to use a macro.
The previous coccinelle semantic patch that improved usage of
log_error_errno()'s return value, only looked for log_error_errno()
invocations with a single parameter after the error parameter. Update
the patch to handle arbitrary numbers of additional arguments.
Turns this:
r = -errno;
log_error_errno(errno, "foo");
into this:
r = log_error_errno(errno, "foo");
and this:
r = log_error_errno(errno, "foo");
return r;
into this:
return log_error_errno(errno, "foo");
Lennart Poettering