In XE5 all conditional compilations such as
{$IFDEF MSWINDOWS}
are replaced with
{$IF defined(MSWINDOWS)}
For example System.Diagnostics.pas in XE4 had
...
implementation
{$IFDEF MSWINDOWS}
uses Winapi.Windows;
{$ENDIF}
{$IFDEF MACOS}
uses Macapi.Mach;
{$ENDIF}
{ TStopwatch }
...
and now in XE5 it looks like:
...
implementation
{$IF defined(MSWINDOWS)}
uses Winapi.Windows;
{$ELSEIF defined(MACOS)}
uses Macapi.Mach;
{$ELSEIF defined(POSIX)}
uses Posix.Time;
{$ENDIF}
{ TStopwatch }
...
Is there any particular reason I should migrate my similar invocations as well?
According to the Delphi documentation:
http://docwiki.embarcadero.com/RADStudio/Rio/en/Conditional_compilation_%28Delphi%29
The conditional directives {$IFDEF}, {$IFNDEF}, {$IF}, {$ELSEIF}, {$ELSE}, {$ENDIF}, and {$IFEND} allow you to compile or suppress code based on the status of a conditional symbol.
The {$IFDEF}
and {$IFNDEF}
only allow you to work with defines previously set by {$DEFINE ...}
.
However the {$IF ..}
directive is much more flexible, because:
Delphi identifiers cannot be referenced in any conditional directives other than {$IF} and {$ELSEIF}.
const LibVersion = 6; //One constant to define the libversion.
{$IF LibVersion >= 10.0}
do stuff that covers LibVersion 10,11 and 12
{$ELSEIF Libversion > 5.0}
do other stuff that covers LibVersion 6,7,8,9
{$IFEND}
If you tried to do that with defines you'd have to do
{$DEFINE Lib1}
{$DEFINE Lib2}
{$DEFINE Lib3}
{$DEFINE Lib4}
{$DEFINE Lib5}
{$DEFINE Lib6} //all previous versions have to be defined.
{$IFDEF Lib10}
do stuff that covers LibVersion 10, 11 and 12
{$ELSE}
{$IFDEF Lib6}
do stuff that covers LibVersion 6,7,8,9
{$ENDIF}
{$ENDIF}
It's just a slightly more advanced version of processing the defines.
The {$IF ..} notation is a bit more powerful and it allows you to query constant expressions and not just defines.
The {$IF ..}
directive was introduced in Delphi 6.
I guess Embarcadero decided to clean up the code base.