Drop the -fundamental suffix from src/fundamental/ headers in favor of names
that match their src/basic/ or src/shared/ counterparts (e.g.
macro-fundamental.h -> macro.h, assert-fundamental.h -> assert-util.h,
cleanup-fundamental.h -> cleanup-util.h). Rename src/basic/{btrfs,label}.{c,h}
to use the -util suffix to match the existing shared/btrfs-util and
shared/label-util siblings. Rename src/shared/mkdir-label.{c,h} to mkdir.{c,h}
and src/shared/tmpfile-util-label.{c,h} to tmpfile-util.{c,h} to match the
corresponding src/basic names.
This saves us from having to come up with separate names for files that do
the same thing across tiers, and it makes it easier to move stuff between
src/fundamental, src/basic and src/shared: consumers just #include "foo.h"
and pick up whichever tier their -I path resolves to first, so call sites
don't need to be updated when an API moves between layers.
Where a higher-tier wrapper exists (e.g. src/basic/macro.h wrapping
src/fundamental/macro.h), the wrapper uses an explicit "../fundamental/foo.h"
or "../basic/foo.h" relative include for the lower-tier header. We can't use
GCC's #include_next directive for this — when the wrapper is reachable both
via same-dir-as-source lookup and via -I (e.g. -Isrc/shared) for the
directory it lives in, #include_next advances by exactly one slot in libcpp's
internal directory chain and lands on the same physical directory it was
already in, never reaching the lower-tier sibling (see make_cpp_dir() in
gcc/libcpp/files.cc:1986).
To make sure the right headers are always picked up, the include directories
are reordered so that e.g. src/shared always takes priority over src/basic and
similar for the other directories.
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.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.
The construct is a POSIX invention, but it's just so useful, let's also
define it in EFI mode, so that we can use similar constructs in EFI mode
and userspace.
Also, make sure the NUL byte iovec becomes an exported constant too.
This is better than the previous situation where this was a macro
resolving to a compount expression, since the lifetime of the expression
is limited to its invoking scope. By turning this into a proper variable
the lifetime becomes unbounded, which makes it easier to use in various
scenarios, such as "if" blocks.
This avoids the ({}) that IOVEC_MAKE_STRING() so far used and might
cause a memory corruption if the parameter passed in is itself allocated
via a compount initialized array or so.
Also, this makes sure both IOVEC_MAKE_STRING() and IOVEC_MAKE() accept
'const' parameters without this causing a compiler warning.
Even more than with the previous commit, this is not a trivial function
and there's no reason to believe this will actually be inlined nor that
it would be beneficial.
The function isn't necessarily fast (it's O(n)), and there's no reason
to have it defined as inline function, since it's neither fast, nor
entirely trivial.
This is preparation for #28891, which adds a bunch more helpers around
"struct iovec", at which point this really deserves its own .c/.h file.
The idea is that we sooner or later can consider "struct iovec" as an
entirely generic mechanism to reference some binary blob, and is the
go-to type for this purpose whenever we need one.
Yu Watanabe
Daan De Meyer
Lennart Poettering
Daan De Meyer
Mike Yuan
Lennart Poettering
Zbigniew Jędrzejewski-Szmek