Merge pull request #435 from ongjunjie/master

minimize file copying on incremental builds

CMakeLists.txt

@@ -30,19 +30,20 @@ include_directories("${CMAKE_CURRENT_SOURCE_DIR}/.")
 # Add custom target to copy all data
 
 set(TARGET_DATA_COPY DATA_COPY)
-if(${CMAKE_CURRENT_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_BINARY_DIR})
-	add_custom_target(
-		${TARGET_DATA_COPY}
-	 	COMMAND ${CMAKE_COMMAND} -E echo "In source build")
-else(${CMAKE_CURRENT_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_BINARY_DIR})
-	make_directory(${CMAKE_CURRENT_BINARY_DIR}/resources/)
-	add_custom_target(
-		${TARGET_DATA_COPY}
-		COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/resources/dream.xml ${CMAKE_CURRENT_BINARY_DIR}/resources/
-		COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/resources/empty.xml ${CMAKE_CURRENT_BINARY_DIR}/resources/
-		COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/resources/utf8test.xml ${CMAKE_CURRENT_BINARY_DIR}/resources/
-		COMMAND ${CMAKE_COMMAND} -E copy ${CMAKE_CURRENT_SOURCE_DIR}/resources/utf8testverify.xml ${CMAKE_CURRENT_BINARY_DIR}/resources/)
-endif(${CMAKE_CURRENT_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_BINARY_DIR})
+set(DATA_COPY_FILES)
+if(NOT ${CMAKE_CURRENT_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_BINARY_DIR})
+	foreach(data dream.xml empty.xml utf8test.xml utf8testverify.xml)
+		set(DATA_COPY_SRC  ${CMAKE_CURRENT_SOURCE_DIR}/resources/${data})
+		set(DATA_COPY_DEST ${CMAKE_CURRENT_BINARY_DIR}/resources/${data})
+		add_custom_command(
+			OUTPUT ${DATA_COPY_DEST}
+			COMMAND ${CMAKE_COMMAND}
+			ARGS -E copy ${DATA_COPY_SRC} ${DATA_COPY_DEST}
+			DEPENDS ${DATA_COPY_SRC})
+		list(APPEND DATA_COPY_FILES ${DATA_COPY_DEST})
+	endforeach(data)
+endif(NOT ${CMAKE_CURRENT_SOURCE_DIR} STREQUAL ${CMAKE_CURRENT_BINARY_DIR})
+add_custom_target(${TARGET_DATA_COPY} DEPENDS ${DATA_COPY_FILES})
 
 ################################
 # Add definitions