Merge pull request #3752 from mshabunin:fix-legacy-cmake-issue

cmake/OpenCVModule.cmake

@@ -20,7 +20,7 @@
 # OPENCV_MODULE_${the_module}_PRIVATE_OPT_DEPS
 # OPENCV_MODULE_${the_module}_IS_PART_OF_WORLD
 # OPENCV_MODULE_${the_module}_CUDA_OBJECTS - compiled CUDA objects list
-# OPENCV_MODULE_${the_module}_CHILDREN - list of submodules for compound modules
+# OPENCV_MODULE_${the_module}_CHILDREN - list of submodules for compound modules (cmake >= 2.8.8)
 # HAVE_${the_module} - for fast check of module availability
 
 # To control the setup of the module you could also set:
@@ -666,7 +666,7 @@ macro(_ocv_create_module)
   if (OPENCV_MODULE_${the_module}_CHILDREN)
     status("Complex module ${the_module}")
     foreach (m ${OPENCV_MODULE_${the_module}_CHILDREN})
-      if (BUILD_${m} AND TARGET ${m}_object) # ambigous?
+      if (BUILD_${m} AND TARGET ${m}_object)
         get_target_property(_sub_links ${m} LINK_LIBRARIES)
         list(APPEND sub_objs $<TARGET_OBJECTS:${m}_object>)
         list(APPEND sub_links ${_sub_links})

cmake/OpenCVUtils.cmake

@@ -788,8 +788,9 @@ function(ocv_add_library target)
 
   add_library(${target} ${ARGN} ${cuda_objs})
 
-  # Add OBJECT library to use in compound modules
-  if (NOT OPENCV_MODULE_${target}_CHILDREN
+  # Add OBJECT library (added in cmake 2.8.8) to use in compound modules
+  if (NOT CMAKE_VERSION VERSION_LESS "2.8.8"
+      AND NOT OPENCV_MODULE_${target}_CHILDREN
       AND NOT OPENCV_MODULE_${target}_CLASS STREQUAL "BINDINGS"
       AND NOT ${target} STREQUAL "opencv_ts"
     )