We use NM_PTRARRAY_LEN(), and I find it a bit ugly that a macro does so
much. Maybe, it's better to have it as a function.
But the macro currently lives in "libnm-std-aux/nm-std-aux.h", which
is header-only. To add it to a C source file, we would have to move
it to another header, but "libnm-std-aux/nm-std-aux.h" is nice because
it gets included by default already.
Keep it in "libnm-std-aux/nm-std-aux.h", but implement it as an inline
function.
The macro now only does (as before) some type checking shenanigans to ensure
that the argument is a pointer to pointers.
In practice, there is probably very little difference compared to
the macro before, likely the code will anyway be inlined.
Replace NM_STATIC_ASSERT_EXPR() by NM_STATIC_ASSERT_EXPR_1() and
NM_STATIC_ASSERT_EXPR_VOID(). NM_STATIC_ASSERT_EXPR_VOID() can be
used as an expression that returns void (that is, a simple statement).
On the other hand, NM_STATIC_ASSERT_EXPR_1() itself retuns
a compile time constant of int value 1. The latter is useful, because
we can use the 1 to combine static assertions in expressions that
are themself compile time constants, like
#define STATIC_CHECK_AND_GET(cond, value) \
(NM_STATIC_ASSERT_EXPR_1(cond) ? (value) : (value))
This is itself a compile time constant if value is a compile
time constant. Also, it does the compile time check that "cond"
is true.
We have variadic macros like NM_UTILS_ENUM2STR() that create a switch
statement. Their implementation relies on the way how __VA_ARGS__
gets expanded to a comma separated list. But that implementation is
not great. Let's instead add (and later use) NM_VA_ARGS_JOIN() which
can join variadic arguments by a configurable separator.
Some compiler versions don't like to dereference and opaque
pointer for typeof:
gcc 8.3.1-5.1.el8 on RHEL:
In file included from ./src/libnm-glib-aux/nm-macros-internal.h:41,
from ./src/libnm-glib-aux/nm-default-glib.h:68,
from ./src/libnm-glib-aux/nm-default-glib-i18n-lib.h:13,
from ./src/libnm-core-impl/nm-default-libnm-core.h:11,
from src/libnm-core-impl/nm-setting-8021x.c:7:
src/libnm-core-impl/nm-setting-8021x.c: In function '_nm_setting_802_1x_cert_value_to_bytes':
./src/libnm-glib-aux/nm-glib.h:417:16: error: dereferencing pointer to incomplete type 'GBytes' {aka 'struct _GBytes'}
typeof(**_pp) *const _p = *_pp; \
^~~~~
src/libnm-core-impl/nm-setting-8021x.c:361:12: note: in expansion of macro 'g_steal_pointer'
return g_steal_pointer(&bytes);
^~~~~~~~~~~~~~~
./src/libnm-glib-aux/nm-glib.h:417:54: error: initialization of 'int * const' from incompatible pointer type 'GBytes *' {aka 'struct _GBytes *'} [-Werror=incompatible-pointer-types]
typeof(**_pp) *const _p = *_pp; \
^
src/libnm-core-impl/nm-setting-8021x.c:361:12: note: in expansion of macro 'g_steal_pointer'
return g_steal_pointer(&bytes);
^~~~~~~~~~~~~~~
./src/libnm-glib-aux/nm-glib.h:415:6: error: returning 'int * const' from a function with incompatible return type 'GBytes *' {aka 'struct _GBytes *'} [-Werror=incompatible-pointer-types]
({ \
~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
typeof(*(pp)) *const _pp = (pp); \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
typeof(**_pp) *const _p = *_pp; \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
_nm_unused const void *const _p_type_check = _p; \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\
~
*_pp = NULL; \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
_p; \
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
})
~~
src/libnm-core-impl/nm-setting-8021x.c:361:12: note: in expansion of macro 'g_steal_pointer'
return g_steal_pointer(&bytes);
^~~~~~~~~~~~~~~
Fixes: 5bc511203e ('all: make nm_steal_pointer() and g_steal_pointer() more typesafe using typeof()')
The previous code would always cast the argument to "void *", and thus
loose some type information.
For example,
gulong variable = 0;
g_steal_pointer(&variable);
would compile, when it shouldn't.
In general, we try to avoid redefining glib macros and headers. But we
really want those extra compile time checks that we can get, so let's do
it.
