[cmake-developers] ninja parallelism and LLVM cmake builds

[Stephen Kelly]

Brad King wrote:

> target_link_libraries(staticB INTERFACE staticA)
> 
> However, that will propagate all usage requirements of A to consumers
> of B.  Depending on the usage requirements specified for A and B that
> may be correct or not.

We could consider making the LINK_ONLY generator expression public in order 
to allow the user to decide the granularity here (possibly encapsulated in a 
INTERFACE_LIBRARY).

 add_library(ifaceA INTERFACE)
 target_link_libraries(ifaceA INTERFACE $<LINK_ONLY:staticA>)
 target_include_directories(ifaceA 
   INTERFACE $<TARGET_PROPERTY:staticA,INTERFACE_INCLUDE_DIRECTORIES>)
 # Propagate the includes from A, but not the compile definitions 
 # or compile options.
 target_link_libraries(staticB ifaceA)

Thanks,

Steve.