Hi All,
I hope I'm doing something really dumb, but I have to say it is stuff
like this that is really disheartening to me. I've been using
FPC/Lazarus for a year now and I have to report that my rate of
development (compared to Delphi) has slowed down significantly...
The following simple program shows that calling an overloaded method
from its "twin" returns garbage:
program project1;
{$mode objfpc}{$H+}
type
TMyClass = class
public
function GetValue_not_overloaded: Integer;
function GetValue_overloaded: Integer; //overload; -- nice feature
not having to specify "overload"!
function GetValue_overloaded(SomeValue: Integer): Integer; //overload;
end;
function TMyClass.GetValue_not_overloaded: Integer;
begin
Result:=1;
end;
function TMyClass.GetValue_overloaded: Integer;
begin
Result:=2;
end;
function TMyClass.GetValue_overloaded(SomeValue: Integer): Integer;
begin
case SomeValue of
1: Result:=GetValue_overloaded; // compiler warning: "Function
result variable does not seem to be initialized" (!)
2: Result:=GetValue_not_overloaded;
else
Result:=3;
end;
end;
var
C: TMyClass;
R: Integer;
begin
C:=TMyClass.Create;
R:=C.GetValue_overloaded; // direct call works
WriteLn('Correct value: ', R);
R:=C.GetValue_overloaded(2); // overloaded function calls non
overloaded function, works
WriteLn('Correct value: ', R);
R:=C.GetValue_overloaded(1); // should return 2, I'm getting random
numbers starting with 422...
WriteLn('Random value: ', R);
ReadLn;
end.
I have tested this with Lazarus 0.9.28.2 (release) and its FPC 2.2.4, a
fresh build of Lazarus from SVN and FPC 2.4.1 as well as FPC 2.5.1 from
SVN. The only difference is the actual incorrect value returned! The
value isn't really random, it is the same each time a specific binary is
run and always start with 422...
FPC 2.2.4: 4221677
FPC 2.4.1: 4223590
FPC 2.5.1: 4220774
Now (assuming I'm not doing something dumb) if this had been a bug in
FPC trunk I can understand, but how can such a (common?) use case not
have been spotted over all these versions?
Perhaps it is bad form to use overloaded functions in such a way, and
perhaps I'm just frustrated because I'm using an old version of Delphi
to debug my code, then when I compile it in Lazarus my app implodes. I
like the latest debugger improvements but I still cannot inspect an
array element. (If there is a way, please let me know).
Regards,
Paul.
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