For one, these functions are not often needed. No need to define them in the
"nm-macros-internal.h" header, which is included everywhere. Move them to
"nm-shared-utils.h", which must be explicitly included.
Also, these functions are usually not called directly, but by passing their
function pointer to a sort function or similar. There is no point in having
defined in the header file.
Previously, NM_PTRARRAY_LEN() would not work if the pointer type is
an opaque type, which is common. For example:
NMConnection *const*connections = ...;
Add an alternative to g_clear_pointer(). The differences are:
- nm_clear_pointer() is more type safe as it does not cast neither the
pointer nor the destroy function. Commonly, the types should be compatible
and not requiring a cast. Casting in the macro eliminates some of the
compilers type checking. For example, while
g_clear_pointer (&priv->hash_table, g_ptr_array_unref);
compiles, nm_clear_pointer() would prevent such an invalid use.
- also, clear the destination pointer *before* invoking the destroy
function. Destroy might emit signals (like weak-pointer callbacks
of GArray clear functions). Clear the destination first, so that
we don't leave a dangling pointer there.
- return TRUE/FALSE depending on whether there was a pointer to clear.
I tested that redefining g_clear_pointer()/g_clear_object() with our
more typesafe nm_* variants still compiles and indicates no bugs. So
that is good. It's not really expected that turning on more static checks
would yield a large number of bugs, because generally our code is in a good
shape already. We have few such bugs, because we already turn all all warnings
and extra checks that make sense. That however is not an argument for
not introducing (and using) a more resticted implementation.
It's slightly more correct to first clear the pointer location
before invoking the destroy function. The destroy function might
emit other callbacks, and at a certain point the pointer becomes
dangling. Avoid this danling pointer, by first clearing the
memory, and then destroing the instance.
Add macros that cast away the constness of a pointer, but
ensure that the type of the pointer is as expected.
Unfortunately, there is no way (AFAIK) to remove the constness of
a variable, without explicitly passing @type to the macro.
When pushing a warning disable with clang, always disable
-Wunknown-warning-option first -- it might be that clang wouldn't warn
of what we're trying to disable because it doesn't recognize it in the
first place. That is entierely okay.
With clang-5.0.0:
CC libnm/tests/libnm_tests_test_secret_agent-test-secret-agent.o
In file included from libnm/tests/test-secret-agent.c:29:
In file included from ./shared/nm-test-libnm-utils.h:23:
./shared/nm-utils/nm-test-utils.h:432:3: error: unknown warning group '-Wunused-but-set-variable', ignored [-Werror,-Wunknown-warning-option]
NM_PRAGMA_WARNING_DISABLE("-Wunused-but-set-variable")
^
./shared/nm-utils/nm-macros-internal.h:223:9: note: expanded from macro 'NM_PRAGMA_WARNING_DISABLE'
_Pragma(_NM_PRAGMA_WARNING_DO(warning))
^
<scratch space>:204:25: note: expanded from here
GCC diagnostic ignored "-Wunused-but-set-variable"
^
1 error generated.
A cmp() implementation, for sorting an array with pointers, where each
pointer is an inteter according to GPOINTER_TO_INT().
That cames for example handy, if you have a GHashTable with keys
GINT_TO_POINTER(). Then you get the list of keys via
g_hash_table_get_keys_as_array() and want to sort them.
Systemd introduced a _fallthrough_ macro in
https://github.com/systemd/systemd/pull/7389.
There might still be some issue with it, but as
I am going to re-import the latest systemd code,
we get them too.
We need it, because "shared/nm-utils/siphash24.c"
will use it too, and that source file does not include
the other systemd macros. So, we will need to re-define
it.
The nm_close() wrapper should behave exactly the same as calling
close() directly. This is well known, documented behavior.
The only addition on top of that, should be the nm_assert() to catch
double-closing.
Prevously, when passing a negative file descriptor, we wouldn't properly
set errno. Also, the call would not show up in strace, which it should
(at least, if libc's close actually makes the syscall).
I would argue, that passing a negative file descriptor is a bug already
and we should never do that. Maybe we should even assert non-negative
fds. I don't do that now, because I am not sufficiently confident.
Anyway, the change should have not practical effect, because we
shouldn't actually pass negative fds already.
There is still a fallback detection in "shared/nm-utils/nm-macros-internal.h",
so that VPN-plugins and applet don't need to bother about adding these
configure checks.
The _NM_GET_PRIVATE() macro already preserved and propagated
the constness of @self to the resulting private pointer.
_NM_GET_PRIVATE_PTR() didn't do that. Extend the macro,
to make that possible.
We need to pass more alias-types. Instead of having numbered
versions, use variadic number of macro arguments.
Also, fix build failure with old compiler:
In file included from src/nm-ip6-config.c:24:
./src/nm-ip6-config.h:44:29: error: controlling expression type 'typeof (ipconf_iter->current->obj)' (aka 'const void *const') not compatible with any generic association type
*out_address = has_next ? NMP_OBJECT_CAST_IP6_ADDRESS (ipconf_iter->current->obj) : NULL;
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fixes: b1810d7a68
_NM_GET_PRIVATE() used typeof() to propagate constness of the @self
pointer. However, that means, it could only be used with a self pointer
of the exact type. That means, you explicitly had to cast from (GObject *)
or from (void *).
The requirement is cumbersome, and often led us to either create @self
pointer we didn't need:
NMDeviceVlan *self = NM_DEVICE_VLAN (device);
NMDeviceVlanPrivate *priv = NM_DEVICE_VLAN_GET_PRIVATE (self);
or casting:
NMDeviceVlanPrivate *priv = NM_DEVICE_VLAN_GET_PRIVATE ((NMDevice *) device);
In both cases we forcefully cast the source variable, loosing help from
the compiler to detect a bug.
For "nm-linux-platform.c", instead we commonly have a pointer of type
NMPlatform. Hence, we always forcefully cast the type via _NM_GET_PRIVATE_VOID().
Rework the macro to use _Generic(). If compiler supports _Generic(), then we
will get all compile time checks as desired. If the compiler doesn't support
_Generic(), it will still work. You don't get the compile-time checking of course,
but you'd notice that something is wrong once you build with a suitable
compiler.
nm_close() is like close(), but throws an assertion if the input fd is
>=0 and invalid. Passing an invalid (i.e. already closed) fd to
close() is a programming error with potentially catastrophic effects,
as another thread may reuse the closed fd.
Introduce a NM_HASH_INIT() function. It makes the places
where we initialize a hash with a certain seed visually clear.
Also, move them from "shared/nm-utils/nm-shared-utils.h" to
"shared/nm-utils/nm-macros-internal.h". We might want to
have NM_HASH_INIT() non-inline (hence, define it in the
source file).
- nm_clear_g_object() is like g_clear_object() but:
- it returns a boolean value, indicating that something was cleared.
- it includes an nm_assert() to check that the pointer is still
valid.
- it uses typeof() instead of blindly casting the argument.
- nm_g_object_ref_set() combines nm_clear_g_object() and resetting
the pointer to a new object, including taking a reference.
- also returns a boolean, indicating whether something changed.
- it gets the order of operations right: first it increses the
ref-count, before unrefing the old object.
- like nm_clear_g_object() and nm_clear_g_free() it first sets
the destination to NULL, instead of leaving a dangling pointer
for the duraction of the unref/free call.
- fix nm_clear_g_free() not to use a possibly dangling pointer.
Striclty speaking, that is undefined behavior.
And relax the type for nm_auto_unref_gtypeclass macro. Like
g_type_class_unref() itself, you usually don't use it with a GTypeClass
base class, but some subtype like GObjectClass.
Compiler wouldn't recognize that the @route/@address argument is always
initialized. The right workaround seems to let the next() functions always
set the value.
In file included from src/nm-ip6-config.c:24:0:
src/nm-ip6-config.c: In function ‘nm_ip6_config_create_setting’:
src/nm-ip6-config.c:734:62: error: the address of ‘address’ will always evaluate as ‘true’ [-Werror=address]
nm_ip_config_iter_ip6_address_for_each (&ipconf_iter, self, &address) {
^
src/nm-ip6-config.h:60:17: note: in definition of macro ‘nm_ip_config_iter_ip6_address_for_each’
for (({ if (address) { *(((const NMPlatformIP6Address **) address)) = NULL; } }), nm_ip_config_iter_ip6_address_init ((iter), (self)); \
^
Fixes: 6e9aa9402a
Returning TRUE for zero makes no sense. Obviously, zero is not a power
of two.
Also, the function is used to check whether a number has only one bit
(flag) set, so, an alternative name would be "has-one-bit-set", which
also should return FALSE for zero. All callers didn't really care for
the previous meaning "has-at-most-one-bit-set".
This also avoids the issue of checking (x >= 0), which causes
-Wtype-limits warnings for unsigned types. Which was avoided
by doing (x == 0 || x > 0), which caused -Wlogical-op warning,
which then was avoided (x == 0 || (x > 0 && 1)). Just don't.
We recently added -Wlogical-op in our build process
(commit #41e7fca59762dc928c9d67b555b1409c3477b2b0).
Seems that old versions of gcc (4.8.x) will hit that warning with our
implementation of our "nm_utils_is_power_of_two" and
"test_nm_utils_is_power_of_two_do" macros.
Fool it just adding an always TRUE check.
I used to use g_strv_length ((char **) p) instead, but that feels
ugly because it g_strv_length() is not designed to operate on
arbitrary pointer arrays.
