Commit Graph

4 Commits

Author SHA1 Message Date
Alejandro Colomar
544709fad3 lib/sizeof.h: memberof(): Add macro
This macro is useful to get the size of a member of a structure
without having a variable of that type.

Reviewed-by: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2024-02-20 18:53:53 +01:00
Alejandro Colomar
e299942189 sizeof.h: Add SIZEOF_ARRAY() macro
This makes it safe to call sizeof() on an array.  Calling sizeof()
directly on an array is dangerous, because if the array changes to be a
pointer, the behavior will unexpectedly change.  It's the same problem
as with NITEMS().

Link: <https://stackoverflow.com/a/57537491>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-09-01 09:39:23 +02:00
Alejandro Colomar
49ea7327d9 sizeof.h: Make NITEMS() and derivative macros safe against pointers
By using must_be_array(), code that calls NITEMS() or STRLEN() with
non-arrays will not compile.

Link: <https://stackoverflow.com/a/57537491>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-09-01 09:39:23 +02:00
Alejandro Colomar
328958ca01 sizeof.h: Move sizeof()-related macros to their own header
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Serge Hallyn <serge@hallyn.com>
Cc: Iker Pedrosa <ipedrosa@redhat.com>
Signed-off-by: Alejandro Colomar <alx@kernel.org>
2023-09-01 09:39:23 +02:00