Thanks again for your answer, Joshua,
When I have tried your first reply, I have got an error message and thought, that I was using the wrong project.xml tag.
But after your second one, I have experimented a little. Now I know, that the openFl does recognize the “–macro” directive correctly.
The problem is, that there seems to be a different issue (maybe a bug (?) )
When I hand set the following tag within the project.xml
<haxeflag name="–macro" value=“Main.macroCallInProjectXml()” />
… the following errors are thrown:
C:/HaxeToolkit/haxe/lib/lime/6,4,0/lime/system/System.hx:713: characters 19-58 : Class<lime._backend.native.NativeCFFI> has no field lime_system_get_device_model
C:/HaxeToolkit/haxe/lib/lime/6,4,0/lime/system/System.hx:744: characters 20-60 : Class<lime._backend.native.NativeCFFI> has no field lime_system_get_device_vendor
C:/HaxeToolkit/haxe/lib/lime/6,4,0/lime/system/System.hx:841: characters 22-63 : Class<lime._backend.native.NativeCFFI> has no field lime_system_get_platform_label
C:/HaxeToolkit/haxe/lib/lime/6,4,0/lime/system/System.hx:905: characters 23-66 : Class<lime._backend.native.NativeCFFI> has no field lime_system_get_platform_version
When I have the same function be executed as a macro on “classical” .hxml compilation, it works well…