Conditional compiling - Delphi has a bug

[KodeZwerg 54]

I did discovered a bug i guess by accident.
I wanted to expand my own .inc file to support FreePascal but compiler did not let me.
 

{$IF Defined(FPC)}
  {$IF Declared(FPC_VERSION)}
    {$IF FPC_VERSION >= 3}  // [Pascal Error] kz.inc(80): E2026 Constant expression expected
      {$DEFINE UNICODE}
    {$IFEND FPC_VERSION}
  {$IFEND FPC_VERSION}
{$IFEND FPC}

A fix was to do it like this, himitsu from german Delphi-Praxis came up with:
 

{$IF Defined(FPC) and Declared(FPC_VERSION) and (FPC_VERSION >= 3)}
  {$DEFINE UniCode} { FreePascal UniCode support }
{$IFEND}

I did open a Report -> Conditional Compiling dont work as expect

If you think i was wrong, please correct me.

Edited August 15, 2022 by KodeZwerg
correction

[Remy Lebeau 1394]

4 hours ago, KodeZwerg said:

I wanted to expand my own .inc file to support FreePascal but compiler did not let me.

{$IF FPC_VERSION >= 3}  // [Pascal Error] kz.inc(80): E2026 Constant expression expected

 

This seems to be the opposite of documented behavior in Delphi: https://docwiki.embarcadero.com/RADStudio/en/IF_directive_(Delphi)

Quote

If the identifiers referenced in the conditional expression do not exist, the conditional expression will be evaluated as False:

  {$IF NoSuchVariable > 5}
    Writeln('This line doesn''t compile');
  {$IFEND}

So, {$IF FPC_VERSION >= 3} SHOULD just evaluate to False, and if it is not then this is likely a regression.

Edited August 16, 2022 by Remy Lebeau

[Fr0sT.Brutal 900]

6 hours ago, Remy Lebeau said:

So, {$IF FPC_VERSION >= 3} SHOULD just evaluate to False, and if it is not then this is likely a regression.

That IF shouldn't be evaluated at all as it lays inside falsy outer block {$IF Declared(FPC_VERSION)}

[Uwe Raabe 2057]

7 hours ago, Remy Lebeau said:

So, {$IF FPC_VERSION >= 3} SHOULD just evaluate to False, and if it is not then this is likely a regression.

If it is a regression, it dates back to Delphi 7 (cannot test for Delphi 6).

Given that conditional expressions were introduced in Delphi 6 I wonder if that has ever worked.

[Brian Evans 105]

The help for the IF directive gives an example of such a construct all on one line instead of split into two IF's. I would suggest trying it that way as it seems to not like just the number check on it's own. 

IF directive (Delphi) - RAD Studio (embarcadero.com) :

  {$IF Declared(FireMonkeyVersion) and (FireMonkeyVersion > 16.0)}
    ...
  {$IFEND}

Edited August 17, 2022 by Brian Evans

[David Heffernan 2345]

3 hours ago, Brian Evans said:

The help for the IF directive gives an example of such a construct all on one line instead of split into two IF's.

You can see exactly this in the original post above. That's not the question being asked though.