CMake: use copy_if_different instead of copy and only run PRE_BUILD on Windows as it is not required on *nix anyway.

tools/assimp_cmd/CMakeLists.txt

@@ -19,10 +19,11 @@ ADD_EXECUTABLE( assimp_cmd
 
 SET_PROPERTY(TARGET assimp_cmd PROPERTY DEBUG_POSTFIX ${ASSIMP_DEBUG_POSTFIX})
 
-#
-ADD_CUSTOM_COMMAND(TARGET assimp_cmd
-	PRE_BUILD
-	COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:assimp> ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} $<TARGET_FILE_DIR:assimp_cmd>)
+IF( WIN32 )
+	ADD_CUSTOM_COMMAND(TARGET assimp_cmd
+		PRE_BUILD
+		COMMAND ${CMAKE_COMMAND} -E copy_if_different $<TARGET_FILE:assimp> ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} $<TARGET_FILE_DIR:assimp_cmd>)
+ENDIF( WIN32 )
 
 TARGET_LINK_LIBRARIES( assimp_cmd assimp ${ZLIB_LIBRARIES})
 SET_TARGET_PROPERTIES( assimp_cmd PROPERTIES

tools/assimp_view/CMakeLists.txt

@@ -43,15 +43,14 @@ ADD_EXECUTABLE(  assimp_viewer WIN32
 
 SET_PROPERTY(TARGET assimp_viewer PROPERTY DEBUG_POSTFIX ${ASSIMP_DEBUG_POSTFIX})
 
-IF( WIN32 )
-	ADD_DEFINITIONS( -D_SCL_SECURE_NO_WARNINGS )
-	ADD_DEFINITIONS( -D_CRT_SECURE_NO_WARNINGS )
-ENDIF( WIN32 )
+ADD_DEFINITIONS( -D_SCL_SECURE_NO_WARNINGS )
+ADD_DEFINITIONS( -D_CRT_SECURE_NO_WARNINGS )
+
 
 #
 ADD_CUSTOM_COMMAND(TARGET assimp_viewer 
 	PRE_BUILD
-	COMMAND ${CMAKE_COMMAND} -E copy $<TARGET_FILE:assimp> ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} $<TARGET_FILE_DIR:assimp_viewer>)
+	COMMAND ${CMAKE_COMMAND} -E copy_if_different $<TARGET_FILE:assimp> ${CMAKE_RUNTIME_OUTPUT_DIRECTORY} $<TARGET_FILE_DIR:assimp_viewer>)
 
 # Link the executable to the assimp + dx libs.
 TARGET_LINK_LIBRARIES ( assimp_viewer assimp ${DirectX_LIBRARY} ${DirectX_D3DX9_LIBRARY} comctl32.lib Winmm.lib  )