NMStrBuf can also contains NUL characters. We thus cannot use g_strndup(),
which uses strncpy() and truncates at the first NUL.
Fixes: 13d25f9d0b ('glib-aux: add support for starting with stack-allocated buffer in NMStrBuf')
NM_STR_BUF_INIT() and nm_str_buf_init() were pretty much redundant. Drop one of
them.
Usually our pattern is that we don't have functions that return structs.
But NM_STR_BUF_INIT() returns a struct, because it's convenient to use
with
nm_auto_str_buf NMStrBuf strbuf = NM_STR_BUF_INIT(...);
So use that variant instead.
Allow to initialize NMStrBuf with an externally allocated array.
Usually a stack buffer. If the NMStrBuf grows beyond the size of
that initial buffer, then it would switch using malloc.
The idea is to support the common case where the result is small enough
to fit on the stack.
I always wanted to do such optimization because the main purpose of
NMStrBuf is to put it on the stack and ad-hoc construct a string.
I just figured, it would complicate the implementation and add
a runtime overhead. But turns out, it doesn't really.
The biggest question is how NMStrBuf should behave with a pre-allocated
buffer? Turns out, most choices can be made in a rather obvious way.
The only non-obvious thing is that nm_str_buf_finalize() would malloc()
a buffer, but that too seems consistent and what a user would probably
expect. As such, this doesn't seem to add unexpected semantics to the API.
We use clang-format for automatic formatting of our source files.
Since clang-format is actively maintained software, the actual
formatting depends on the used version of clang-format. That is
unfortunate and painful, but really unavoidable unless clang-format
would be strictly bug-compatible.
So the version that we must use is from the current Fedora release, which
is also tested by our gitlab-ci. Previously, we were using Fedora 34 with
clang-tools-extra-12.0.1-1.fc34.x86_64.
As Fedora 35 comes along, we need to update our formatting as Fedora 35
comes with version "13.0.0~rc1-1.fc35".
An alternative would be to freeze on version 12, but that has different
problems (like, it's cumbersome to rebuild clang 12 on Fedora 35 and it
would be cumbersome for our developers which are on Fedora 35 to use a
clang that they cannot easily install).
The (differently painful) solution is to reformat from time to time, as we
switch to a new Fedora (and thus clang) version.
Usually we would expect that such a reformatting brings minor changes.
But this time, the changes are huge. That is mentioned in the release
notes [1] as
Makes PointerAligment: Right working with AlignConsecutiveDeclarations. (Fixes https://llvm.org/PR27353)
[1] https://releases.llvm.org/13.0.0/tools/clang/docs/ReleaseNotes.html#clang-format
We already have nm_str_buf_append_c2() and nm_str_buf_append_c4()
to support 2 or 4 characters.
I'd like to also have one for 3 characters.
At this point, just make it a variadic macro. This now supports 1 up to
4 characters, and it will be easy to extend further.
