[CMake] linking static libs into shared libs on Linux

[Dan Kegel]

On Tue, Jul 7, 2015 at 12:36 PM, Steve Borho <steve at borho.org> wrote:
> /bin/ld: common/CMakeFiles/common.dir/x86/pixel-a.asm.o: relocation
> R_X86_64_PC32 against symbol `x265_pw_1' can not be used when making a
> shared object; recompile with -fPIC
> ...
> 2 - is there some invocation that will force cmake to build the static
>   libraries such that they are still safe for linking into a shared
>   library?
>
>   I've already tried these unsuccessfully:
>     set(CMAKE_POSITION_INDEPENDENT_CODE TRUE)
>     set_target_properties(x265-static PROPERTIES POSITION_INDEPENDENT_CODE TRUE)
>     set_target_properties(x265-static PROPERTIES LINK_FLAGS "-fPIC")
>
> 3 - is there another intermediate format that cmake can output that
>   preserves -fPIC, or some way to access the object libraries of the
>   other external builds?

Try
     set_target_properties(x265-static PROPERTIES COMPILE_FLAGS "-fPIC")

Alternately, something like
set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fPIC")
when compiling the files in question.