tree 40a2c31ed4eaf12134198094ecd06d57649cde51
parent ea7babba13cb78557addf915a20bc51b457ffd03
author Sebastian Bøe <sebastian.boe@nordicsemi.no> 1551190508 +0100
committer Anas Nashif <anas.nashif@intel.com> 1551675240 -0500

cmake: Don't assert when empty libraries are detected

The empty-library check was introduced because in earlier versions of
CMake the error message for empty libraries was very cryptic. But in
3.13.2 CMake now reports:

-- Configuring done
CMake Error at ../../cmake/extensions.cmake:357 (add_library):
  No SOURCES given to target: drivers__entropy
Call Stack (most recent call first):
  ../../cmake/extensions.cmake:334 (zephyr_library_named)
  ../../drivers/entropy/CMakeLists.txt:1 (zephyr_library)

which should be clear enough.

In addition to being redundant, our empty library check is run earlier
than CMake's check, so it will falsely report libraries to be empty,
when in fact, in an out-of-tree driver use-case, they will not
actually be empty at Generation time.

CMake runs it's check at generation time and is not affected by this
problem, so we remove the check.

This is a step, but not a complete solution, to resolving #8379.

Signed-off-by: Sebastian Bøe <sebastian.boe@nordicsemi.no>