SPDK uses constructor functions for registration functionality
in several different areas - RPCs, bdev modules, event tracing,
etc. Since these functions are not explicitly referenced, the
linker will remove these constructor functions from the linked
application unless their library is included using the
--whole-archive linker option.
SPDK has tried to minimize the number of libraries linked with
--whole-archive to only those that are necessary. But there
are still a lot of exceptions that we need to work around. The
benefit to trying to restrict it is minimal - for example,
an nvmf_tgt binary built before this patch is 4746320 bytes
on my system, but linking all of the libraries with
--whole-archive only increases it to 4784080 bytes - a difference
of less than 1%.
Note that DPDK also links all libraries with --whole-archive by
default.
This will also simplify some upcoming changes around shared
library dependencies - we will be able to blindly use
--whole-archive when linking the shared library as well.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: Iab0dbbace06a3d15c835491e55683ab4cf9e53fe
Reviewed-on: https://review.gerrithub.io/432917
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
7962ce312d