Florian Bezdeka authored Sep 27, 2023 and Jan Kiszka committed Sep 28, 2023

COBALT_IMPL_TIME64():
  This macro is based on COBALT_IMPL() and will add the necessary
  __wrap_ function as weak symbol to the cobalt implementation
  (starting with __cobalt_) when y2038 support has been requested.
  This allows the usage of the __RT() macro in combination with
  y2038/time64 wrappers.

COBALT_DECL_TIME64():
  This macro is based on COBALT_DECL() and allows the usage of __STD()
  in combination with y2038/time64 wrappers.

Both macros will fall back to their basements if y2038 support was
not requested.

Examples, assuming code is located in application code:
  select():       will be redirected by glibc to __select64() when
                  y2038 support is requested. We additionally wrap the
                  __select64() function so __wrap___select64() will be
                  called - which is a weak symbol aliased to
                  __cobalt_select(). That allows users to overwrite
                  __wrap___select64() if they need to.

  __RT(select()): result after preprocessor: __cobalt_select()
                  __cobalt_select() is y2038 safe when y2038 has been
                  requested.

Signed-off-by: Florian Bezdeka <florian.bezdeka@siemens.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>