Bug with constref?

[LemonParty]

I am trying to compile the next code:

Code: Pascal  [Select][+][-]

1. {$mode ObjFPC}{$H+}
2.  
3. function F(constref A): UInt32;
4. var
5.   D: UInt32 absolute A;
6. begin
7.   Result:= D;
8. end;
9.  
10. function F2(constref Arr): Integer;
11. var
12.   aArr: array [Byte] of Byte absolute Arr;
13. begin
14.   Result:= F(aArr[0]);
15. end;
16.  
17. begin
18.        
19. end.

And getting

(14,17) Error: Can't assign values to const variable

When use const instead of constref code compiles.
Is it bug?

[ASerge]

Simplified version:

Code: Pascal  [Select][+][-]

1. {$mode ObjFPC}{$H+}
2.  
3. procedure F(constref A); // or var A
4. begin
5. end;
6.  
7. procedure F2(const Arr: TIntegerArray); // var solve problem
8. begin
9.   F(Arr[0]);
10. end;
11.  
12. begin
13.  
14. end.

[marcov]

And getting

(14,17) Error: Can't assign values to const variable

When use const instead of constref code compiles.
Is it bug?

Passing to a constref means taking the address. That might not be allowed for CONST parameters. My gut feeling that if it is a bug, it is the quality of the error message.

[LemonParty]

Reported on bugtracker.