[fpc-pascal] "class" methods for objects

[Helmut Hartl]

Am 16.07.10 12:46, schrieb Michael Van Canneyt:
>> Always learning something new.
>>      
> One is never too old to learn :-)
>
> Michael.
But one is always able to age faster,
while boldly going to where no man has gone
baldly before :-) (spelling intentional)

While testing with a simplified usage pattern I encountered a compiler 
problem.
Should I report a bug - or am I missing something ?

helmut


--snip--
program project_static2;
{$static on}
type
   Etyp=(t1,t2,t3);

   function ProxyObject_IsInSubrange(const typ:Etyp):boolean;
   begin
     ProxyObject_IsInSubrange:=typ<=t2;
   end;
type
   ProxyObject=object
     function IsInSubrange(const typ:Etyp):boolean;static;
   end;

   RealObject=object
     mytyp:Etyp;
     function IsInSubrange:boolean;
   end;

function RealObject.IsInSubrange: boolean;
begin
   IsInSubrange:=ProxyObject.IsInSubrange(mytyp);  // 
project1.lpr(25,15) Error: Class isn't a parent class of the current class
   IsInSubrange:=ProxyObject_IsInSubrange(mytyp); //works but very ugly 
(due to lots of similar code)
end;

function ProxyObject.IsInSubrange(const typ: Etyp): boolean;
begin
   IsInSubrange:=typ<=t2;
end;

var o:RealObject;

begin
  writeln(ProxyObject.IsInSubrange(t3));
  o.mytyp:=t3;
  writeln (o.IsInSubrange);
end.
--snap--

Output:
--- fpc 2.4.0:

BigMac:test helly$ /usr/local/lib/fpc/2.4.0/ppc386  project_static2.lpr
Free Pascal Compiler version 2.4.0 [2009/12/20] for i386
Copyright (c) 1993-2009 by Florian Klaempfl
Target OS: Darwin for i386
Compiling project_static2.lpr
project_static2.lpr(22,29) Error: Class isn't a parent class of the 
current class
Fatal: Compilation aborted
An unhandled exception occurred at $000994AD :
EAccessViolation : Access violation
   $000994AD
   $001264B6
   $0012A57D
   $0012A58E
   $0012A58E
   $0012A58E
   $0012ADF0
   $00119AD9
   $00119D89
   $001118E1
   $00114BAA
   $0011555C
   $001158B2
   $0011176D
   $00114BAA
   $001507FC
   $000310F3

--- fpc 2.5.1 + debuginfo
BigMac:test helly$ /usr/local/lib/fpc/2.5.1/ppc386  project_static2.lpr
Free Pascal Compiler version 2.5.1 [2010/07/16] for i386
Copyright (c) 1993-2009 by Florian Klaempfl
Target OS: Darwin for i386
Compiling project_static2.lpr
project_static2.lpr(2,2) Warning: Illegal compiler directive "$STATIC"
project_static2.lpr(22,29) Error: Class isn't a parent class of the 
current class
Fatal: Compilation aborted
An unhandled exception occurred at $000B2CED :
EAccessViolation : Access violation
   $000B2CED  TYPECHECKPASS_INTERNAL,  line 70 of 
/Users/helly/pascal/fpc_trunk/compiler/pass_1.pas
   $0014B006  FACTOR,  line 2317 of 
/Users/helly/pascal/fpc_trunk/compiler/pexpr.pas
   $0014EB9A  SUB_EXPR,  line 2772 of 
/Users/helly/pascal/fpc_trunk/compiler/pexpr.pas
   $0014EBAB  SUB_EXPR,  line 2774 of 
/Users/helly/pascal/fpc_trunk/compiler/pexpr.pas
   $0014EBAB  SUB_EXPR,  line 2774 of 
/Users/helly/pascal/fpc_trunk/compiler/pexpr.pas
   $0014EBAB  SUB_EXPR,  line 2774 of 
/Users/helly/pascal/fpc_trunk/compiler/pexpr.pas
   $0014F261  EXPR,  line 2902 of 
/Users/helly/pascal/fpc_trunk/compiler/pexpr.pas
   $0013CD97  STATEMENT,  line 1111 of 
/Users/helly/pascal/fpc_trunk/compiler/pstatmnt.pas
   $0013D0D9  STATEMENT_BLOCK,  line 1219 of 
/Users/helly/pascal/fpc_trunk/compiler/pstatmnt.pas
   $001346EB  BLOCK,  line 246 of 
/Users/helly/pascal/fpc_trunk/compiler/psub.pas
   $00137B6A  TCGPROCINFO__PARSE_BODY,  line 1440 of 
/Users/helly/pascal/fpc_trunk/compiler/psub.pas
   $00138516  READ_PROC,  line 1753 of 
/Users/helly/pascal/fpc_trunk/compiler/psub.pas
   $00138902  READ_DECLARATIONS,  line 1862 of 
/Users/helly/pascal/fpc_trunk/compiler/psub.pas
   $00134519  BLOCK,  line 171 of 
/Users/helly/pascal/fpc_trunk/compiler/psub.pas
   $00137B6A  TCGPROCINFO__PARSE_BODY,  line 1440 of 
/Users/helly/pascal/fpc_trunk/compiler/psub.pas
   $0017679C  COMPILE,  line 403 of 
/Users/helly/pascal/fpc_trunk/compiler/parser.pas
   $000334A3  COMPILE,  line 249 of 
/Users/helly/pascal/fpc_trunk/compiler/compiler.pas