COMP: implement support for OPTIONAL_DEPENDS

CMake/OTBModuleAPI.cmake

@@ -10,6 +10,11 @@ macro(_otb_module_use_recurse mod)
     foreach(dep IN LISTS ${mod}_DEPENDS)
       _otb_module_use_recurse(${dep})
     endforeach()
+    foreach(dep IN LISTS ${mod}_OPTIONAL_DEPENDS)
+      if (${otb-module}_ENABLED)
+        _otb_module_use_recurse(${dep})
+      endif()
+    endforeach()
     if(${mod}_INCLUDE_DIRS)
       include_directories(${${mod}_INCLUDE_DIRS})
     endif()
@@ -39,11 +44,12 @@ endmacro()
 # otb_module_load(<module>)
 #
 # Loads variables describing the given module:
-#  <module>_LOADED         = True if the module has been loaded
-#  <module>_DEPENDS        = List of dependencies on other modules
-#  <module>_LIBRARIES      = Libraries to link
-#  <module>_INCLUDE_DIRS   = Header search path
-#  <module>_LIBRARY_DIRS   = Library search path (for outside dependencies)
+#  <module>_LOADED           = True if the module has been loaded
+#  <module>_DEPENDS          = List of dependencies on other modules
+#  <module>_OPTIONAL_DEPENDS = List of dependencies on other modules
+#  <module>_LIBRARIES        = Libraries to link
+#  <module>_INCLUDE_DIRS     = Header search path
+#  <module>_LIBRARY_DIRS     = Library search path (for outside dependencies)
 macro(otb_module_load mod)
   if(NOT ${mod}_LOADED)
     include("${OTB_MODULES_DIR}/${mod}.cmake" OPTIONAL)

CMake/OTBModuleInfo.cmake.in

 set(@otb-module@_LOADED 1)
 set(@otb-module@_DEPENDS "@otb-module-DEPENDS@")
+set(@otb-module@_OPTIONAL_DEPENDS "@otb-module-OPTIONAL_DEPENDS@")
 set(@otb-module@_LIBRARIES "@otb-module-LIBRARIES@")
 set(@otb-module@_INCLUDE_DIRS "@otb-module-INCLUDE_DIRS@")
 set(@otb-module@_LIBRARY_DIRS "@otb-module-LIBRARY_DIRS@")

CMake/OTBModuleMacros.cmake

@@ -26,12 +26,13 @@ macro(otb_module _name)
   set(OTB_MODULE_${otb-module}_DECLARED 1)
   set(OTB_MODULE_${otb-module-test}_DECLARED 1)
   set(OTB_MODULE_${otb-module}_DEPENDS "")
+  set(OTB_MODULE_${otb-module}_OPTIONAL_DEPENDS "")
   set(OTB_MODULE_${otb-module-test}_DEPENDS "${otb-module}")
   set(OTB_MODULE_${otb-module}_DESCRIPTION "description")
   set(OTB_MODULE_${otb-module}_EXCLUDE_FROM_DEFAULT 0)
   set(OTB_MODULE_${otb-module}_ENABLE_SHARED 0)
   foreach(arg ${ARGN})
-    if("${arg}" MATCHES "^(DEPENDS|TEST_DEPENDS|DESCRIPTION|DEFAULT)$")
+    if("${arg}" MATCHES "^(DEPENDS|OPTIONAL_DEPENDS|TEST_DEPENDS|DESCRIPTION|DEFAULT)$")
       set(_doing "${arg}")
     elseif("${arg}" MATCHES "^EXCLUDE_FROM_DEFAULT$")
       set(_doing "")
@@ -48,6 +49,8 @@ macro(otb_module _name)
       message(AUTHOR_WARNING "Unknown argument [${arg}]")
     elseif("${_doing}" MATCHES "^DEPENDS$")
       list(APPEND OTB_MODULE_${otb-module}_DEPENDS "${arg}")
+    elseif("${_doing}" MATCHES "^OPTIONAL_DEPENDS$")
+      list(APPEND OTB_MODULE_${otb-module}_OPTIONAL_DEPENDS "${arg}")
     elseif("${_doing}" MATCHES "^TEST_DEPENDS$")
       list(APPEND OTB_MODULE_${otb-module-test}_DEPENDS "${arg}")
     elseif("${_doing}" MATCHES "^DESCRIPTION$")
@@ -61,6 +64,7 @@ macro(otb_module _name)
     endif()
   endforeach()
   list(SORT OTB_MODULE_${otb-module}_DEPENDS) # Deterministic order.
+  list(SORT OTB_MODULE_${otb-module}_OPTIONAL_DEPENDS) # Deterministic order.
   list(SORT OTB_MODULE_${otb-module-test}_DEPENDS) # Deterministic order.
 endmacro()
 
@@ -102,12 +106,26 @@ macro(otb_module_impl)
   add_custom_target(${otb-module}-all ALL SOURCES ${_srcs})
 
   otb_module_use(${OTB_MODULE_${otb-module}_DEPENDS})
+  
+  foreach(dep IN LISTS OTB_MODULE_${otb-module}_OPTIONAL_DEPENDS)
+    if (${dep}_ENABLED)
+      otb_module_use(${dep})
+    endif()
+  endforeach()
 
   if(NOT DEFINED ${otb-module}_LIBRARIES)
     set(${otb-module}_LIBRARIES "")
+    
     foreach(dep IN LISTS OTB_MODULE_${otb-module}_DEPENDS)
       list(APPEND ${otb-module}_LIBRARIES "${${dep}_LIBRARIES}")
     endforeach()
+    
+    foreach(dep IN LISTS OTB_MODULE_${otb-module}_OPTIONAL_DEPENDS)
+      if (${dep}_ENABLED)
+        list(APPEND ${otb-module}_LIBRARIES "${${dep}_LIBRARIES}")
+      endif()
+    endforeach()
+
     if(${otb-module}_LIBRARIES)
       list(REMOVE_DUPLICATES ${otb-module}_LIBRARIES)
     endif()
@@ -146,7 +164,7 @@ macro(otb_module_impl)
   endif()
 
   if(EXISTS ${${otb-module}_SOURCE_DIR}/app/CMakeLists.txt AND NOT ${otb-module}_NO_SRC)
-    # TODO : check the use of the following line
+    # TODO : check the utility of the following line
     # set_property(GLOBAL APPEND PROPERTY OTBTargets_MODULES ${otb-module})
     add_subdirectory(app)
   endif()
@@ -183,6 +201,7 @@ macro(otb_module_impl)
   set(otb-module-EXPORT_CODE-install "${${otb-module}_EXPORT_CODE_INSTALL}")
 
   set(otb-module-DEPENDS "${OTB_MODULE_${otb-module}_DEPENDS}")
+  set(otb-module-OPTIONAL_DEPENDS "${OTB_MODULE_${otb-module}_OPTIONAL_DEPENDS}")
   set(otb-module-LIBRARIES "${${otb-module}_LIBRARIES}")
   set(otb-module-INCLUDE_DIRS-build "${${otb-module}_INCLUDE_DIRS}")
   set(otb-module-INCLUDE_DIRS-install "\${OTB_INSTALL_PREFIX}/${${otb-module}_INSTALL_INCLUDE_DIR}")