[cmake-developers] Policy for INTERFACE_LINK_LIBRARIES

[Brad King]

On 12/06/2012 05:00 PM, Stephen Kelly wrote:
> Currently it doesn't seem to work. Using current master with this:
> 
>  add_library(picon SHARED libone.cpp)
>  add_library(picoff SHARED libtwo.cpp)
>  target_link_libraries(picoff picon)
>  
>  export(TARGETS
>    picon
>    NAMESPACE foo_
>    FILE foo_iface.cmake
>  )
> 
>  export(TARGETS
>    picoff
>    NAMESPACE bar_
>    FILE bar_iface.cmake
>  )
> 
> Results in an error:
> 
>  CMake Error at CMakeLists.txt:99 (export):
>    export called with target "picoff" which requires target "picon" that is
>    not in the export list.

IIRC the topic that added dependent export support was only
finished for the install(EXPORT) command and not for export().
It added a test for the install case mixing namespaces:

 http://cmake.org/gitweb?p=cmake.git;a=commitdiff;h=955b9662

It appears to work.  The install tree contains one export with:

 # Create imported target Req::testLibRequired
 ADD_LIBRARY(Req::testLibRequired STATIC IMPORTED)
 ...
 # Import target "Req::testLibRequired" for configuration "Debug"
 SET_PROPERTY(TARGET Req::testLibRequired APPEND PROPERTY IMPORTED_CONFIGURATIONS DEBUG)
 SET_TARGET_PROPERTIES(Req::testLibRequired PROPERTIES
   IMPORTED_LINK_INTERFACE_LANGUAGES_DEBUG "C"
   IMPORTED_LOCATION_DEBUG "${_IMPORT_PREFIX}/lib/libtestLibRequired.a"
   )

and a dependent export with:

 # Create imported target testLibDepends
 ADD_LIBRARY(testLibDepends STATIC IMPORTED)
 ...
 # Make sure the targets which have been exported in some other
 # export set exist.
 IF(NOT TARGET "Req::testLibRequired" )
   IF(CMAKE_FIND_PACKAGE_NAME)
     SET( ${CMAKE_FIND_PACKAGE_NAME}_FOUND FALSE)
     SET( ${CMAKE_FIND_PACKAGE_NAME}_NOT_FOUND_MESSAGE "Required imported target \"Req::testLibRequired\" not found ! ")
   ELSE()
     MESSAGE(FATAL_ERROR "Required imported target \"Req::testLibRequired\" not found ! ")
   ENDIF()
 ENDIF()
 ...
 # Import target "testLibDepends" for configuration "Debug"
 SET_PROPERTY(TARGET testLibDepends APPEND PROPERTY IMPORTED_CONFIGURATIONS DEBUG)
 SET_TARGET_PROPERTIES(testLibDepends PROPERTIES
   IMPORTED_LINK_INTERFACE_LANGUAGES_DEBUG "C"
   IMPORTED_LINK_INTERFACE_LIBRARIES_DEBUG "Req::testLibRequired"
   IMPORTED_LOCATION_DEBUG "${_IMPORT_PREFIX}/lib/libtestLibDepends.a"
   )

This will need to work in the new interface.

-Brad