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.
Say that r should be declared at the top of the function.
Don't say that fixed buffers result in truncation, right after saying that they
must only be used if size is known.
Adjust order of examples to be consistent.
Primarily:
1. Mention that we prefer if return parameters carry "ret_" as prefix in
their name
2. Clarify that debug-level logging is always OK, and irrelevant to when
deciding whether a function is logging or non-logging.
