cmake/FindLtdl.cmake

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##########################################################################

SET(LTDL_LIBS "ltdl")

IF(LTDL_PATH)

  SET(LTDL_INCLUDES "${LTDL_PATH}/include")
  SET(LTDL_LIB_DIR "${LTDL_PATH}/lib")
  SET(LTDL_LFLAGS "-L${LTDL_LIB_DIR}")

  IF(NOT LTDL_LINK_DYNAMIC AND EXISTS "${LTDL_LIB_DIR}/libltdl.a")
    SET(LTDL_LIBS "${LTDL_LIB_DIR}/libltdl.a")
  ENDIF(NOT LTDL_LINK_DYNAMIC AND EXISTS "${LTDL_LIB_DIR}/libltdl.a")

ELSE(LTDL_PATH)

  INCLUDE (CheckIncludeFiles)
  CHECK_INCLUDE_FILES(ltdl.h HAVE_LTDL_H)

  IF(NOT HAVE_LTDL_H)
    MESSAGE(FATAL_ERROR "ltdl.h could not be found")
  ENDIF(NOT HAVE_LTDL_H)

  INCLUDE (CheckLibraryExists)
  CHECK_LIBRARY_EXISTS(ltdl lt_dlopen "" HAVE_LTDL_LIB)

  IF(NOT HAVE_LTDL_LIB)
    MESSAGE(FATAL_ERROR "ltdl lib could not be found")
  ENDIF(NOT HAVE_LTDL_LIB)

ENDIF(LTDL_PATH)

TRY_COMPILE(COMPILE_RESULT ${CMAKE_SOURCE_DIR}/cmake/CMakeTmp ${CMAKE_SOURCE_DIR}/cmake/needdl.c
            CMAKE_FLAGS -DINCLUDE_DIRECTORIES=${LTDL_INCLUDES}
            -DLINK_DIRECTORIES=${LTDL_LIB_DIR}
            -DLINK_LIBRARIES=${LTDL_LIBS}
            OUTPUT_VARIABLE     COMPILE_OUTPUT)

# Perhaps to add try_compile with dl would be safer
IF(COMPILE_RESULT) 
  MESSAGE(STATUS "Checking if need to link dl - FALSE")
ElSE(COMPILE_RESULT) 
  MESSAGE(STATUS "Checking if need to link dl - TRUE")
  SET(LTDL_LIBS ${LTDL_LIBS} "dl")
ENDIF(COMPILE_RESULT)