Define cmake target as PIC if BUILD_SHARED_LIBS

What language does this apply to? Generated C/C++ code and the specific cmake target.

Describe the problem you are trying to solve. When I link to the generated cmake target and set the BUILD_SHARED_LIBS variable globally I get linker errors because the protobuf created code is not relocateable.

Describe the solution you'd like In my user code I use something like the following:

# ensure relocateable code
if (BUILD_SHARED_LIBS)
  set_property(TARGET ${PROTO_TARGET} PROPERTY POSITION_INDEPENDENT_CODE TRUE)
endif ()

But this could be integrated in the cmake part of this project directly.

Describe alternatives you've considered It's not a big problem. But may be helpful for people that do not have that much cmake experience.

Additional context Nothing.