Translations: handle cross compiling

CMakeLists.txt

@@ -436,11 +436,7 @@ add_definition_if_function_found(strptime HAVE_STRPTIME)
 add_definitions(-DAUTO_INITIALIZE_EASYLOGGINGPP)
 
 # Generate header for embedded translations
-include(ExternalProject)
-ExternalProject_Add(generate_translations_header
-  SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/translations"
-  BINARY_DIR "${CMAKE_CURRENT_BINARY_DIR}/translations"
-  INSTALL_COMMAND cmake -E echo "")
+add_subdirectory(translations)
 include_directories("${CMAKE_CURRENT_BINARY_DIR}/translations")
 
 add_subdirectory(external)

translations/CMakeLists.txt

@@ -30,7 +30,17 @@ cmake_minimum_required(VERSION 2.8.7)
 
 project(translations)
 
-add_executable(generate_translations_header generate_translations_header.c)
+# when crosscompiling import the executable targets from a file
+IF(CMAKE_CROSSCOMPILING)
+  message(WARNING "CrossCompiling")
+  SET(IMPORT_EXECUTABLES "${CMAKE_CURRENT_BINARY_DIR}/ImportExecutables.cmake" CACHE FILEPATH "Point it to the export file from a native build")
+  INCLUDE(${IMPORT_EXECUTABLES})
+ENDIF(CMAKE_CROSSCOMPILING)
+
+# only build the generator if not crosscompiling
+IF(NOT CMAKE_CROSSCOMPILING)
+  add_executable(generate_translations_header generate_translations_header.c)
+ENDIF(NOT CMAKE_CROSSCOMPILING)
 
 find_program(LRELEASE lrelease)
 if(LRELEASE STREQUAL "LRELEASE-NOTFOUND")
@@ -61,3 +71,8 @@ add_custom_command(TARGET generate_translations_header
   COMMAND generate_translations_header ${qm_files}
   WORKING_DIRECTORY "${CMAKE_CURRENT_BIN_DIR}"
   COMMENT "Generating embedded translations header")
+
+# export the generator target to a file, so it can be imported (see above) by another build
+IF(NOT CMAKE_CROSSCOMPILING)
+  EXPORT(TARGETS generate_translations_header FILE ${CMAKE_CURRENT_BINARY_DIR}/ImportExecutables.cmake )
+ENDIF(NOT CMAKE_CROSSCOMPILING)