[fpc-pascal] Hack for C-like macro functions — will it work in future?

[Роман]

As we all know, C preprocessor allows function-like macros, including 
ones with empty expansion. They can be very convenient for things that 
you'll want to disable depending on conditional defines, such as logging 
or assertions.

#ifdef DEBUG
     #define dprf(...) print_debug_message(__VA_ARGS__)
#else
     #define dprf(...)
#endif

I have a temptation to use this in FPC too. Here's a trick:

{$macro on}
{$ifdef DEBUG}
     {$define Log := ActualLog}
{$else}
     {$define Log := ;//}
{$endif}

if A then
   Log('will work until followed by ELSE at all or any statements on the 
same line (because of ; and //, respectively).');
if B then
   Log('And should not be carried over to the next line, of course!');

Because constant {$ifdef DEBUG} ActualLog(...); {$endif} are rather 
cumbersome.

This is by design? Can I rely on this behavior in the future? ._.