{
    $Id$
    This file is part of the Free Pascal run time library.
    Copyright (c) 2001 by the Free Pascal development team

    This include file contains the implementation for variants
    support in FPC as far as it is part of the system unit

    See the file COPYING.FPC, included in this distribution,
    for details about the copyright.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

 **********************************************************************}

var
   variantmanager : tvariantmanager;

procedure invalidvariantop;
  begin
     HandleErrorFrame(221,get_frame);
  end;

procedure vardisperror;
  begin
     HandleErrorFrame(222,get_frame);
  end;


{ ---------------------------------------------------------------------
    Compiler helper routines.
  ---------------------------------------------------------------------}

procedure varclear(var v : tvardata);
begin
   if not(v.vtype in [varempty,varerror,varnull]) then
     invalidvariantop;
end;


procedure variant_init(var v : tvardata);[Public,Alias:'FPC_VARIANT_INIT'];
  begin
     { calling the variant manager here is a problem because the static/global variants
       are initialized while the variant manager isn't assigned }
     fillchar(v,sizeof(variant),0);
  end;


procedure variant_clear(var v : tvardata);[Public,Alias:'FPC_VARIANT_CLEAR'];
  begin
    if assigned(VarClearProc) then
      VarClearProc(v)
  end;


procedure variant_addref(var v : tvardata);[Public,Alias:'FPC_VARIANT_ADDREF'];
  begin
    if assigned(VarAddRefProc) then
      VarAddRefProc(v);
  end;


Procedure fpc_write_text_variant(Len : Longint;var f : Text;const v : variant); iocheck; [Public,Alias:'FPC_WRITE_TEXT_VARIANT']; compilerproc;
Begin
  If (InOutRes<>0) then
   exit;
  case TextRec(f).mode of
    { fmAppend gets changed to fmOutPut in do_open (JM) }
    fmOutput:
      if len=-1 then
        variantmanager.write0variant(f,v)
      else
        variantmanager.writevariant(f,v,len);
    fmInput:
      InOutRes:=105
    else InOutRes:=103;
  end;
End;


function fpc_variant_to_dynarray(const v : variant;typeinfo : pointer) : pointer;compilerproc;
  begin
    variantmanager.vartodynarray(result,v,typeinfo);
  end;


function fpc_dynarray_to_variant(dynarr : pointer;typeinfo : pointer) : variant;compilerproc;
  begin
    variantmanager.varfromdynarray(result,dynarr,typeinfo);
  end;


function fpc_variant_to_interface(const v : variant) : iinterface;compilerproc;
  begin
    variantmanager.vartointf(result,v);
  end;


function fpc_interface_to_variant(const i : iinterface) : variant;compilerproc;
  begin
    variantmanager.varfromintf(result,i);
  end;


{ ---------------------------------------------------------------------
    Overloaded operators.
  ---------------------------------------------------------------------}


{ Integer }

operator :=(const source : byte) dest : variant;

begin
  Variantmanager.varfromInt(Dest,Source,1);
end;


operator :=(const source : shortint) dest : variant;

begin
  Variantmanager.varfromInt(Dest,Source,-1);
end;


operator :=(const source : word) dest : variant;

begin
  Variantmanager.varfromInt(Dest,Source,2);
end;


operator :=(const source : smallint) dest : variant;
begin
  Variantmanager.varfromInt(Dest,Source,-2);
end;


operator :=(const source : dword) dest : variant;
begin
  Variantmanager.varfromInt(Dest,Source,4);
end;


operator :=(const source : longint) dest : variant;
begin
  Variantmanager.varfromInt(Dest,Source,-4);
end;


operator :=(const source : qword) dest : variant;
begin
  Variantmanager.varfromWord64(Dest,Source);
end;


operator :=(const source : int64) dest : variant;
begin
  Variantmanager.varfromInt64(Dest,Source);
end;

{ Boolean }

operator :=(const source : boolean) dest : variant;
begin
  Variantmanager.varfromBool(Dest,Source);
end;


operator :=(const source : wordbool) dest : variant;

begin
  Variantmanager.varfromBool(Dest,Boolean(Source));
end;


operator :=(const source : longbool) dest : variant;

begin
  Variantmanager.varfromBool(Dest,Boolean(Source));
end;


{ Chars }

operator :=(const source : char) dest : variant;

begin
  VariantManager.VarFromPStr(Dest,Source);
end;


operator :=(const source : widechar) dest : variant;

begin
  VariantManager.VarFromWStr(Dest,Source);
end;

{ Strings }

operator :=(const source : shortstring) dest : variant;

begin
  VariantManager.VarFromPStr(Dest,Source);
end;


operator :=(const source : ansistring) dest : variant;

begin
  VariantManager.VarFromLStr(Dest,Source);
end;


operator :=(const source : widestring) dest : variant;

begin
  VariantManager.VarFromWStr(Dest,Source);
end;

{ Floats }

{$ifdef SUPPORT_SINGLE}
operator :=(const source : single) dest : variant;
begin
  VariantManager.VarFromReal(Dest,Source);
end;
{$endif SUPPORT_SINGLE}


{$ifdef SUPPORT_DOUBLE}
operator :=(const source : double) dest : variant;
begin
  VariantManager.VarFromReal(Dest,Source);
end;
{$endif SUPPORT_DOUBLE}


{$ifdef SUPPORT_EXTENDED}
operator :=(const source : extended) dest : variant;
begin
  VariantManager.VarFromReal(Dest,Source);
end;
{$endif SUPPORT_EXTENDED}


{$ifdef SUPPORT_COMP}
Operator :=(const source : comp) dest : variant;
begin
  VariantManager.VarFromReal(Dest,Source);
end;
{$endif SUPPORT_COMP}


{ Misc. }
{ Fixme!!!
operator :=(const source : currency) dest : variant;
  begin
  end;

operator :=(const source : tdatetime) dest : variant;
  begin
  end;
}
{**********************************************************************
                       from Variant assignments
 **********************************************************************}

{ Integer }

operator :=(const source : variant) dest : byte;

begin
  dest:=variantmanager.vartoint(source);
end;


operator :=(const source : variant) dest : shortint;

begin
  dest:=variantmanager.vartoint(source);
end;


operator :=(const source : variant) dest : word;

begin
  dest:=variantmanager.vartoint(source);
end;


operator :=(const source : variant) dest : smallint;

begin
  dest:=variantmanager.vartoint(source);
end;


operator :=(const source : variant) dest : dword;

begin
  dest:=variantmanager.vartoint(source);
end;


operator :=(const source : variant) dest : longint;

begin
  dest:=variantmanager.vartoint(source);
end;


operator :=(const source : variant) dest : qword;

begin
  dest:=variantmanager.vartoword64(source);
end;


operator :=(const source : variant) dest : int64;

begin
  dest:=variantmanager.vartoint64(source);
end;


{ Boolean }

operator :=(const source : variant) dest : boolean;

begin
  dest:=variantmanager.vartobool(source);
end;


operator :=(const source : variant) dest : wordbool;

begin
  dest:=variantmanager.vartobool(source);
end;


operator :=(const source : variant) dest : longbool;

begin
   dest:=variantmanager.vartobool(source);
end;


{ Chars }

operator :=(const source : variant) dest : char;

Var
  S : String;

begin
  VariantManager.VarToPStr(S,Source);
  If Length(S)>0 then
    Dest:=S[1];
end;


operator :=(const source : variant) dest : widechar;

Var
  WS : WideString;

begin
  VariantManager.VarToWStr(WS,Source);
  If Length(WS)>0 then
    Dest:=WS[1];
end;


{ Strings }

operator :=(const source : variant) dest : shortstring;

begin
  VariantManager.VarToPStr(Dest,Source);
end;

operator :=(const source : variant) dest : ansistring;

begin
  VariantManager.vartolstr(dest,source);
end;

operator :=(const source : variant) dest : widestring;

begin
  variantmanager.vartowstr(dest,source);
end;

{ Floats }

{$ifdef SUPPORT_SINGLE}
operator :=(const source : variant) dest : single;
begin
  dest:=variantmanager.vartoreal(source);
end;
{$endif SUPPORT_SINGLE}


{$ifdef SUPPORT_DOUBLE}
operator :=(const source : variant) dest : double;
begin
  dest:=variantmanager.vartoreal(source);
end;
{$endif SUPPORT_DOUBLE}


{$ifdef SUPPORT_EXTENDED}
operator :=(const source : variant) dest : extended;
begin
  dest:=variantmanager.vartoreal(source);
end;
{$endif SUPPORT_EXTENDED}


{$ifdef SUPPORT_COMP}
operator :=(const source : variant) dest : comp;
begin
  dest:=comp(variantmanager.vartoreal(source));
end;
{$endif SUPPORT_COMP}

{ Misc. }
operator :=(const source : variant) dest : currency;

begin
  dest:=variantmanager.vartocurr(source);
end;

(* FIXME !!!
operator :=(const source : variant) dest : tdatetime;

begin
  dest:=variantmanager.currtovar(source);
end;
*)
{**********************************************************************
                               Operators
 **********************************************************************}

operator or(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opor);
  end;

operator and(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opand);
  end;

operator xor(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opxor);
  end;

operator not(const op : variant) dest : variant;
  begin
     dest:=op;
     variantmanager.varnot(dest);
  end;

operator shl(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opshiftleft);
  end;

operator shr(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opshiftright);
  end;

operator +(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opadd);
  end;

operator -(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opsubtract);
  end;

operator *(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opmultiply);
  end;

operator /(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opdivide);
  end;

operator div(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opintdivide);
  end;

operator mod(const op1,op2 : variant) dest : variant;
  begin
     dest:=op1;
     variantmanager.varop(dest,op2,opmodulus);
  end;

operator -(const op : variant) dest : variant;
  begin
     dest:=op;
     variantmanager.varneg(dest);
  end;

operator =(const op1,op2 : variant) dest : boolean;
  begin
     dest:=variantmanager.cmpop(op1,op2,opcmpeq);
  end;

operator <(const op1,op2 : variant) dest : boolean;
  begin
     dest:=variantmanager.cmpop(op1,op2,opcmplt);
  end;

operator >(const op1,op2 : variant) dest : boolean;
  begin
     dest:=variantmanager.cmpop(op1,op2,opcmpgt);
  end;

operator >=(const op1,op2 : variant) dest : boolean;
  begin
     dest:=variantmanager.cmpop(op1,op2,opcmpge);
  end;

operator <=(const op1,op2 : variant) dest : boolean;
  begin
     dest:=variantmanager.cmpop(op1,op2,opcmplt);
  end;


{**********************************************************************
                      Variant manager functions
 **********************************************************************}

procedure GetVariantManager(var VarMgr: TVariantManager);
begin
  VarMgr:=VariantManager;
end;

procedure SetVariantManager(const VarMgr: TVariantManager);
begin
  VariantManager:=VarMgr;
end;

function IsVariantManagerSet: Boolean;
var
   i : longint;
begin
   I:=0;
   Result:=True;
   While Result and (I<(sizeof(tvariantmanager) div sizeof(pointer))-1) do
     begin
       Result:=Pointer(ppointer(@variantmanager+i*sizeof(pointer))^)<>Pointer(@invalidvariantop);
       Inc(I);
     end;
end;


procedure initvariantmanager;
  var
     i : longint;
  begin
     VarDispProc:=@vardisperror;
     DispCallByIDProc:=@vardisperror;
     tvardata(Unassigned).VType:=varEmpty;
     tvardata(Null).VType:=varNull;
     for i:=0 to (sizeof(tvariantmanager) div sizeof(pointer))-1 do
       ppointer(@variantmanager+i*sizeof(pointer))^:=@invalidvariantop;
     pointer(variantmanager.varclear):=@varclear
  end;


{
  $Log$
  Revision 1.25  2005-02-24 22:36:36  florian
    + some variant stuff fixed and added

  Revision 1.24  2005/02/14 17:13:29  peter
    * truncate log

  Revision 1.23  2005/02/01 20:22:24  florian
    + interface <-> variant conversion from Danny Milosavljevic

  Revision 1.22  2005/01/15 18:47:26  florian
    * several variant init./final. stuff fixed

  Revision 1.21  2005/01/08 20:43:44  florian
    + init/cleaning code for variants added

  Revision 1.20  2005/01/07 21:15:46  florian
    + basic rtl support for variant <-> interface implemented

}