I am trying to compile a Delphi matrix package using fpc 1.9.4 and I don't know if I misunderstand FPC's overloading or if there is an FPC problem. The code is located here:

http://www.fssc.demon.co.uk/Delphi/delphi.htm#TMatrix

Lines 84-85 define a transpose method:

84 function transpose : TMatrix; {overload;}
85 function transpose (m : TMatrix) : TMatrix; {overload;}

(I commented out the overload keyword.. doesn't seem to matter.). I don't see any forward declaration of 'transpose':

misc code]$ grep -i transpose mat.pas

                   function  transpose : TMatrix; overload;
                   function  transpose (m : TMatrix) : TMatrix;

overload;
{ Transpose matrix 'Self', Self is thus destroyed and replaced }
{ Usage: A.transpose
}
function TMatrix.Transpose : TMatrix;
{ move data from transpose to Self }
{ Transpose the matrix 'm' into Self
}
{ Usage: T.transpose (A); Tranposes A and puts result into T }
{ Will also accept T.transpose (T)
}
function TMatrix.Transpose (m : TMatrix) : TMatrix; raise EMatrixSizeError.Create ('Destination matrix has incorrect dimensions for transpose');
{ If the user is trying to transpose itself.... }

    tmp.Transpose (st);
    Self.Transpose (ns);

This is the output when I try to compile:

 misc code]$ fpc -gl -S2 -Cr -Co mat.pas
Free Pascal Compiler version 1.9.4 [2004/05/30] for i386
Copyright (c) 1993-2004 by Florian Klaempfl
Target OS: Linux for i386
Compiling mat.pas
mat.pas(85,41) Error: Duplicate identifier "M"
mat.pas(85,30) Error: Function is already declared Public/Forward
"TMatrix.transpose:TMatrix"
mat.pas(87,38) Error: Duplicate identifier "M"
mat.pas(89,38) Error: Duplicate identifier "M"
mat.pas(90,38) Error: Duplicate identifier "M"
mat.pas(91,30) Error: Function is already declared Public/Forward
"TMatrix.mult(Extended):TMatrix"
mat.pas(93,38) Error: Duplicate identifier "M"
mat.pas(103,40) Error: Duplicate identifier "M"
mat.pas(117,73) Error: Duplicate identifier "c"
mat.pas(118,48) Error: Duplicate identifier "r"
mat.pas(118,73) Error: Duplicate identifier "c"
mat.pas(119,59) Error: Duplicate identifier "r"
mat.pas(127,1) Fatal: There were 12 errors compiling module, stopping

Any ideas on getting fpc to compile this? I'm confused by the reference to 'm'?

-Alan

When you compile using -S2 parameter you are compiling in objfpc mode. This mode is not exactly compatible with Delphi. In this particular case, the problem is that in objfpc mode method parameters can't have the same name as the object properties and fields (that's what "Duplicate identifier ..." errors mean). That's often very nice safety-check, however it makes many Delphi code invalid in objfpc mode.

Solution is to compile in delphi mode:
fpc -Mdelphi mat.pas
works OK.

--- Michalis Kamburelis wrote

Solution is to compile in delphi mode: fpc -Mdelphi mat.pas works OK.

Thanks! -Sd worked great... in fact FPC may produce better diagnostics than Delphi..

-Alan

This leads me to the question:

Is it "legal" to link together objects compiled in different modes? (I haven't tried if it is possible at all ...)

For example Alan would compile his matrix stuff in delphi mode and link to other object files compiled in objpas mode?

TIA,
Marc

This is not a problem. The generated code is the same, independent of the mode. The mode only affects the parsing, and how identifiers are interpreted.

Michael.

04-09-01 09.29, skrev följande:

But can Delphi classes be used if you are in e g TP mode ?

Am Mi, den 01.09.2004 schrieb um 09:29:
[...]

Ah, I see.

Thank you very much,
Marc

No. You need objfpc or delphi mode for that.

Michael.

04-09-01 13.40, skrev följande:

Then I suggest to add this to the documentation about the language modes.

The doc says that unit ObjPas is loaded, but nothing about which type of classes which can be uses.

Olle