Previously, we did not have a hard dependency on C99. Nowadays, we
actually build against C11, so we have <stdbool.h>. These definitions
are no longer necessary nor do we care about building against plain
C89.
We redefine _G_BOOLEAN_EXPR(), so let it use NM_BOOLEAN_EXPR().
Also, we use G_LIKELY() (and thus NM_BOOLEAN_EXPR()) inside nm_assert(),
and we use nm_assert() in some macros. To be able to nest nm_assert()
calls, we need to create unique variable names for NM_BOOLEAN_EXPR().
Having assertion macros that are disabled by default, is not
only useful for our glib code, but should also be available
for nm-std-aux. Move the macros.
- add unit test for nm_utils_parse_next_line()
- as line delimiter also accept "\r\n" and "\r" (beside "\n", "\0" and
EOF).
- fix returning lines with embedded "\0" characters. The line ends
on the first "\n" or "\0", whatever comes first. The code before
didn't ensure that with:
line_end = memchr (line_start, '\n', *inout_len);
if (!line_end)
line_end = memchr (line_start, '\0', *inout_len);
We want to parse "/proc/cmdline". That is space separated with support
for quoting and escaping. Our implementation becomes part of stable
behavior, and we should interpret the kernel command line the same way
as the system does. That means, our implementation should match
systemd's.
In the previous form, NM_STR_BUF_INIT() was a macro. That makes sense,
however it's not really possible to make that a macro without evaluating
the reservation length multiple times. That means,
NMStrBuf strbuf = NM_STR_BUF_INIT (nmtst_get_rand_uint32 () % 100, FALSE);
leads to a crash. That is unfortunate, so instead make it an inline
function that returns a NMStrBut struct. Usually, we avoid functions
that returns structs, but here we do it.
If g_vsnprintf() returns that it wants to write 5 characters, it
really needs space for 5+1 characters. If we have 5 characters
available, it would have written "0123\0", which leaves the buffer
broken.
Fixes: eda47170ed ('shared: add NMStrBuf util')
Previously, for simplicity, NMStrBuf did not support buffers without any
data allocated. However, supporting that has very little
overhead/complexity, so do it.
Now you can initialize buffers to have no data allocated, and when
appending data, it will automatically grow.
Iterating hash tables gives an undefined order. Often we want to have
a stable order, for example when printing the content of a hash or
when converting it to a "a{sv}" variant.
How to achieve that best? I think we should only iterate the hash once,
and not require additional lookups. nm_utils_named_values_from_strdict()
achieves that by returning the key and the value together. Also, often
we only need the list for a short time, so we can avoid heap allocating
the list, if it is short enough. This works by allowing the caller to
provide a pre-allocated buffer (usually on the stack) and only as fallback
allocate a new list.
If the value pointer is const, it is commonly inconvenient and requires
a cast. Requiring casts on a common base does not increase type safety,
but is annoying.
g_steal_pointer() is marked as GLIB_AVAILABLE_STATIC_INLINE_IN_2_44,
that means we get a deprecated warning. Avoid that. We anyway
re-implement the macro so that we can use it before 2.44 and so
that it always does the typeof() cast.
When parsing user input if is often convenient to allow stripping whitespace.
Especially with escaped strings, the user could still escape the whitespace,
if the space should be taken literally.
Add support for that to nm_utils_buf_utf8safe_unescape().
Note that this is not the same as calling g_strstrip() before/after
unescape. That is, because nm_utils_buf_utf8safe_unescape() correctly
preserves escaped whitespace. If you call g_strstrip() before/after
the unescape, you don't know whether the whitespace is escaped.
We want to use the function to unescape (compress) secrets. As such, we want
to be sure that no secrets are leaked in memory due to growing the buffer with
realloc. In fact, reallocation should never happen. Assert for that.
As reallocation cannot happen, we could directly fill a buffer with
API like nm_utils_strbuf_*(). But NMStrBuf has low overhead even in this
case.
We have nm_str_not_empty() which is the inverse of that. The purpose
of nm_str_not_empty() is to normalize a string to either return
%NULL or a non-empty string, like
const char *
get_name (Object *obj)
{
return nm_str_not_empty (obj->name);
}
Sometimes, we however want to check whether a string is not empty.
So, we previously had two choices:
1) use a temporary variable:
const char *tmp;
tmp = get_string ();
if (tmp && tmp[0])
...
The problem with this variant is that it's more verbose (by requiring a
temporary variable). Another downside is that there are multiple ways
how to check for an empty string (!tmp[0], tmp[0] == '\0', !strlen (tmp),
strlen (tmp) == 0), and sure enough they are all in use.
2) use !nm_str_not_empty(). But this double negation looks really odd
and confusing.
Add nm_str_is_empty() instead.
Macros preferably behave function-like, for example in that they evaluate
arguments exactly ones. Sometimes, we want to evaluate arguments
lazily, like in NM_IN_SET() or nm_g_set_error_take_lazy(). But it
is almost always undesirable to evaluate an argument more than once.
Fix NM_STR_HAS_PREFIX() for that.
Also, rename the local variable to not use the name "_str",
which may be a common name that the caller would like to use.
