On Tue, Dec 01, 2020 at 04:14PM +0000, Christoph Hellwig wrote:
> Why not use the kernels own BUILD_BUG_ON instead of this idiom?
BUILD_BUG_ON() was conceived before there was builtin compiler-support
in the form of _Static_assert() (static_assert()), which has several
advantages (compile-time performance, optional message) but most
importantly, that it can be used at module/global scope (which
BUILD_BUG_ON() cannot).
>From include/linux/build_bug:
/**
* static_assert - check integer constant expression at build time
*
[...]
*
* Contrary to BUILD_BUG_ON(), static_assert() can be used at global
* scope, but requires the expression to be an integer constant
* expression (i.e., it is not enough that __builtin_constant_p() is
* true for expr).
[...]
.. and there are plenty of global/module scoped users of it already.
Thanks,
-- Marco
